How do i add like a service fee or percentage in a smart contract on every transaction!

Smart Contracts
1

so ive made a pretty simple erc20 token, i was wondering if i can add a fee for every transaction that uses my token,
and also i wanted to add blacklist to my code

(im a total noob so please help me out)

2

Every transaction of uses from your token may trigger the function transfer or transferFrom.