Contractor Payment Schedule Question

[Jimmy Epolito]

Hello Gang, I am closing on my first flip in Columbus Ga this Friday and I need to put together a contract for the GC who is overseeing the project. I am wanting advice on percentages to pay upfront and during the project. This is mostly a cosmetic rehab and should only take 4-6 weeks. I am using a HML so the draws will come with fees. Total rehab budget is $20k. Scope of work will be painting full interior, LVP throughout, New Kitchen Cabinets, Granite Counter Top, Update Bath with New Vanity/tub, add drywall to one block wall in basement bedroom, new kitchen appliances, replace 2 interior doors, minor electrical fixes, and minor exterior touch up.

GC is purchasing materials.  

How much should I give up front and then what is a fair payment schedule for the GC which protects me as well?