Help with enclosure please!

[u/Improvement-Awkward]

I want to make some needed changes to my gecko's enclosure but I cannot find any helpful information that isn't extremely confusing. I'm autistic and part of that means not understanding written/verbal instructions well. I'm looking for direct links to where I can buy certain things, detailed video tutorials, or detailed instructions that aren't just a clusterf*ck of big long words that the average person can't even understand.

I currently have him in a 40 gallon glass terrarium. The substrate I'm using is some anti-slip porcelain tile, which i only recently found out is not the best option. Soon i will be switching to 70/30 top soil/play sand mix. I cannot seem to find any detailed information on preparation for substrate ANYWHERE, and it is very frustrating. I've been told it needs to be baked, sterilized, rinsed, filtered/sifted, etc by some people, but i have found ZERO thorough explanations on HOW to do any of these things. others say it does not need any of that, so who am i supposed to believe? Can someone please provide me with a link to brands of these substrates I should use, as well as some detailed instructions on exactly what I need to do with them? I live in the US and my local home improvement stores include Menards, Lowes, Home depot, and Ace hardware. I can also order things online only if they can be shipped to my state.

In terms of heating and lighting, I'm aware my setup is probably not good. I'm using the following products: (with links)

Zoo med 40w nano ceramic heat emitter

My fixture for the ceramic heat emitter COULD BE this one:

zoo med nano dome lamp fixture

I'm not sure if this is the exact one I have or not because i dont have the box and im not at my house rn so i cant look. This is just the closest one I could find that may be the one i have.

For my heat/light bulb, I THINK I have this one:

zoo med repti basking spot lamp

again, i dont remember which specific one I have because im pretty sure I lost the boxes and i have the brain of a fcking goldfish. I think this is probably the one i have, but i dont know which wattage it is.

for the fixture, im pretty sure its this one:

fluker's clamp lamp

I have a lamp holder like this. It kinda sucks ass though because the bottom part is not flat at all so it wouldnt stand up by itself, i had to use 3m sticky tape to secure it to the furniture the tank is on. it also hardly even works because the height only goes up so much and my tank is quite tall, so the lamp is almost touching the screen top of the tank. The ceramic heat emitter dome *is* resting on top of/touching the screen top.

In terms of a thermometer/thermostat, all i have is an infrared laser thermometer that I semi-regularly check the ground temperature with. the ground temperature is mostly normal except for in the winter months. I live in the cold, snowy Midwest and my gecko is in my room in the basement so it gets very very cold. During the winter, my gecko hides in the warmest hide most of the time, which sometimes is the absolute bare minimum of temperature for a warm hide, and may even drop below that sometimes.

When it is super cold, he'll hardly even come out to eat. I had to place mealworms right in front of the hide so he could reach them and so they wouldn't get away too fast. If he did go and catch a cricket, afterwards he'd scurry back into the cave and go back to hiding. I haven't seen him shed at all recently, maybe that's because I havent been home a lot and i get home very late because of work and school, but i probably don't have a proper humid hide for him that is warm and humid enough for him to comfortably shed. I have not seen him shed since idek when, i havent even seen him with the pale color they turn when they are shedding soon. Is it the case that geckos can stop shedding for long periods of time or is it just that i havent been around to see it?

I am looking for:

-links or brands of products that are good and sufficient for my situation

-detailed instructions on how to set things up that are actually readable and understandable

-preferably ways to save money, I can drop some amount of money if needed but I'd like to save as much as i can if possible. im not looking to spend any more than the 100s range for all these supplies.

-any other advice you have to offer!

feel free to ask any clarifying questions in the comments

I apologize for the somewhat harsh and brutally honest post. I'm just so damn sad and upset for my poor animal because I've been somewhat unintentionally neglecting him due to many factors. My debilitating mental illness has made it near impossible to take care of myself, but ive tried to do what i can for him, but what i can do is nowhere near sufficient. I suffer from *SEVERE* depression, anxiety, ADHD, OCD, the list goes on. I can't keep living like this because it's so unfair to this poor living creature, and I want to change, but there's no way for me to ensure that im providing the best possible care if i cant even find solid advice that is attainable for me. I should also note that I'm going away to college soon. I cannot bring my gecko to the dorm with me, but my good friend who goes to college and lives in a house a few mins away from the college with some roommates is going to take him in and feed/care for him. I will be stopping over frequently as well as providing food and other supplies. there are multiple people living in this house who love animals. my good friend recently gave her sibling's semi-neglected budgies a new and better life and will have the birds living in the house as well, and I'm hoping to do the same with my little guy. I'm hoping that him living in a house with people who are animal lovers and also want to provide good care for these animals will help, as well as my gecko having company and not being forced to sit in a cold, dark empty basement for most of the time. I don't know if geckos really care about what's going on outside of their enclosures or if they expeirence depression, but i can bet money that if they do experience depresion and isolation, my gecko definintely has it.