Deductions & credits

as long as the items relate to your You Tube activity they should qualify as start-up costs until you go live or a regular business expense once live. Business expenses are covered by IRS code section 162 - basically ordinary and necessary expenses are deductible but there have been many court cases over the meaning of those words.

see this link for clothing 

https://www.keepertax.com/posts/write-off-clothes-for-work