I wanna make profit on ebay but will they charge me? read the description?

• charge transfer
• sell shares online

Ok so i want to make a little business out of ebay like buy stuff and sell it for a higher price so i can make a little profit on it :) so anyways say if i sold nail polish or something for like $5 how much will they charge me for listing it and what if no one bought it will they still charge me for it cause im like really confused about it also say if i sold a singlet for like $15 how much profit will ebay make and like how much will they charge me and take away from it like if i didn't sell it they will still charge me for listing right....? and say if i did sell it how much will they get?

PLEASE HELP EBAY IS SO CONFUSING! :(

I wanna make profit on ebay but will they charge me? read the description?