1. What type of challenge do you face when you want to buy or sell bitcoin or any other crypto?
I find no challenge anymore when I'd like to buy/sell bitcoin and even with altcoins. Websites that are into the business are reachable and easy to transact so if there's a challenging thing for me now that would the confirmation time though this happens when I pay cheap fee and I know the solution and that's to pay a recommended fee.
2. How the buy and sell process looks like? it is easy or not?
Peer to peer, transfer to exchange, automated also on exchanges. It's easy.
3. Can you share with me how your process look like?
The process is simple, you send your bitcoin on exchange and trade it with your desired crypto/altcoin (stable or not) then you can choose to cash out with fiat.
4. Which app or site do you like and why?
Binance for the meanwhile.