Go through it, keep what is truly sir use and definitely try to sell or donate what you can, especially physical media since even without a lot of monetary value those are items that typically aren’t being made any more so are of a finite number. There are those of us that like collecting physical media and have the space to store and enjoy it so helping it get a second life is a better choice than just dumping it in a landfill to rot (almost literally) forever.
Otherwise the key is to relish the nostalgia of going through it but don’t let it color your decisions on what to keep too much. It’s okay to hold on to some things that truly matter to you just for sentimental reasons, but you shouldn’t try to keep it all. My wife and I each have a plastic tote in our basement of keepsakes, we try to limit sentimental things to just that one tote each to help keep it manageable.
Honestly it depends on what you want your wallet to hold. I use a Ridge wallet (I had a knockoff for a while but treated myself to a forged carbon Ridge with blue inclusions that I really like the look of).
I only carry 4-5 cards though, and a couple folded bills in the cash strap. It goes in my front pocket because that’s just more comfortable and is a somewhat more secure place to keep a wallet (not perfect, but marginally harder to pickpocket than a butt pocket and less likely to just slip out while going about your day). It’s made of metal, carbon fiber, and some replaceable elastic bands. It protects against RFID skimming, and is overall about the size of a trifold wallet. I consider it a BIFL wallet because it fits my needs in a wallet, that style may not work for you though.