Is a bad practice to hold the coins on a exchange because that way you are not the owner of your coins even if they are in your account, they can get hacked, the exchange can lock your account, or the exchange can close.
The wallet I recomend for you is atomic wallet, google it and you will find a lot of info, I. That wallet you can hold different coins, that's why I recomend that one.
I wouldn't recommend someone using a custodial wallet as well because there aren't a lot of differences between centralized exchanges and custodial wallets since your assets aren't safe in any of the two as you don't get to keep your keys and phrases to yourself. So, newbies are to be told not to keep their funds in exchanges and also not in custodial wallets, but they should use non-custodial wallets for that.
Keeping all your assets shouldn't be the primary goal, the primary goal should be the security of the assets, and if they are secure, it doesn't matter even if they are kept in different wallets. So, it's important that newbies learn about non-custodial wallets and start using them instead of making excuses such as they are not user-friendly, it requires technical knowledge, etc. Learn everything, if you want to be in this industry.