Welcome to the Plastic Navy! I am by far not an expert but here are the items I carry and/or do for safety. Take your yak empty to a boat ramp or in a pool where you are in shoulder deep water and flip it, dressed like you plan on kayaking. Then practice how to get back in just in case you ever have an accident on the water. I believe a life vest and whistle are all thats required. I've never had a game warden check me, but here's my list of safety stuff.
Whistle attached to PFD
https://www.mariner-sails.com/sea-dog-whistle-life-jacket.html Knife (personally i carry a dive knife)
A orange flag with Light on it
https://www.mariner-sails.com/yak-attack-visipole-ii-light-mast-floating-base-in.html leash for paddle
ziplock bag or these for all thing you want dry
https://www.amazon.com/gp/product/B089QJWZ4X/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1Hand bilage pump
extra rope or paracord
if you go offshore VHF radio
I keep a small dry bag in my hull with water weld (putty to patch a hole), 1st aid kit, sunscreen, extra hat, leatherman, and towel.