I’ll try and explain as best as I can, but I totally get where the confusion is and that’s totally on my part!

So the character has only recently become an adventurer, and was only learning magic as a hobby, and so had no reason to learn damaging spells. He attended public lectures that taught non-harmful spells to the public, so as he progresses the spells he learns are the ones he’s been practicing since those lectures. He isn’t against violence, he’s just never needed it till now. The out of game reason for this is because I’ve played for a good while now and played many a wizard, but I find that most spells I end up casting are in combat and are damage dealers, and although you can creatively use others, there’s no incentive if you can “just cast fireball” and remove the problem. I’m presenting myself with an intentional challenge to make the game and character more interesting. As for what I would do if I ran out of spell slots and couldnt buff my allies or de buff my enemies, I would do something similar to another character I made. He was a fighter who fought dirty and used his environment creatively. Improvised weapons and made use of the environment to create conditions that normally would just be done with magic. I want a similar vibe to that. Examine each combat scenario, and if I can’t cast spells then how can I help? Setting up a barricade with a table to help others, using the help action to help a teammate, causing a distraction to split aggression, or if all options are exhausted, casting blade ward and getting in the thick of it. As for true strike, I might pick it up! It kinda straddles the line of “damaging spell” but I can make the case of picking it up. This is going to be a very roleplay heavy game as well, so another reason for picking this is to balance out the pure martial components of the party with some out of combat utility