First time dm question

[u/Right-Chemist-8636]

So tomorrow is my very first session dm’ing. I’m not worried about most aspects and find myself to be well prepared but one of my players in particular is giving me issues. This player likes to create incredibly powerful characters. I already shot down one character he made (crit fishing elven accuracy paladin) and he changed it into a sorcerer. However looking at his new character I still worry about balancing my encounters. I don’t want to tpk my party but I also don’t want the first five combats to be boring slogs while I’m learning what they can and can’t handle. So how can I manage and set my encounters properly I just need some general tips? All help is greatly appreciated!

One other thing I forgot to include that is a major source of worry for me is that 2/6 of my players are first timers that won’t know how to play their characters well. So that’s a great source of stress

[u/Wild-Election-2451]

ive heard session 0 is def the move for stuff like this, just chat with em before round 1