Cell phone tax write off?

So a little about my background.. I’m an OF creator and a lot of my money is through cash app paypal etc. Which now this year I’m going to be taxed on. I’m not really sure what I’m doing but I’m trying to be prepared for this upcoming year.

I’m wondering if I could write off phones I buy every 1-2 weeks. They are 100% only used for my business. I buy $40 cricket phones + $30 service card which totals about $80 (every 1-2 weeks). Unless I can find them discounted. I’m wondering if I can write all of them off? and I’m wondering what “proof” I exactly have to have in order for the irs to accept it? I’m already saving my receipts.

Also for anybody who has anymore tips about what I can write off being an “entertainer” would be appreciated!! I’m planning on getting a business license and opening a business account so I can keep better track of all my money.