I have a Bitcoin wallet through an exchange, can I have a wallet not attached to an exchange? or multiple wallets? if the exchange has problems = I have problems

Yes, and you're right its the same if you have a web wallet so I recommend that use a mobile wallet like Mycelium, desktop wallet like electrum or a hardware wallet like ledger nano s tho and trezor tho you have to buy the hardware wallets first. I'm assure you that this wallets are the safest one. Look here
https://bitcoin.org/en/choose-your-walletTo tell you honestly its uo to you to decide, try to find some local bitcoin wallet users, or ask some of your friends who are using some bitcoin wallets in your local area, because sometimes there are also bitcoin wallets that are only best for your own area, or sometimes there are also an offer bitcoin wallet available in your own country, but what he said is also recommendable and working too.