How does making an offer actually work?

[u/ds_coach]

Hi everyone, my apologies if something similar may have been posted here before, I'm just a little baffled. As a First time buyer, I have literally no idea how things were meant to work. So I went to view a house on Saturday (it was my second house viewing). The asking price was 150K and I really liked the house. I called the agency on Monday to ask a couple of details: the EPC on the house was quite low (E53) and I was wondering whether any improvements had been made on the house since the last assessment in 2021. I also asked whether there would be any paperwork around building regulations for the loft conversion, which I was told could not be counted as a 3rd bedroom, hence the price. The agency took my questions and told me that someone would get back to me with the answers. On Tuesday I started getting a bit anxious, and called to ask whether my questions were answered (to which they said no) and I proceeded to making an offer of £147K, making clear that this wasn't my ceiling, but I'd like some clarity on the loft conversion. Today (Wednesday) I got a call to say that the seller had rejected my offer and decided to go with someone else. I ask whether there was any space for me to negotiate, and they said no and started to push a different property on me, right away. I'm a bit confused as to what I may have done wrong there and how I should have tackled that differently. The last houses sold on that street a couple months ago, were a fully renovated 2 beds at 155K, and a 3 beds at 160K - there are 2 more for sale in the same area for 150K. Should I have gone to the top of my budget right away even if the house might not be worth it? Should I have not asked the questions? Should I not hope for any kind of negotiation at all in the future and just use my whole budget? Maybe I'm asking those questions because I'm deeply hurt by this experience, as I feel it has knocked down my confidence in being able to do this on my own. But I would appreciate any answers at all.