Reddit – Dive into anything

i was using paypal and as you know it has so many problems hold people’s money and whatnot so i quit using it and want to switch to bitcoin my problem is if im buying something or selling something how to know the fee i will pay when i buy something or the extra money i have to put on the item im selling so i get the exact money im selling my product for not less because of the fee the buyer had to pay

i use exodus wallet is it good ? or there’s a better one

please answer i really want to know explain it to me like im a 6 years old if you could