Is the Samsung galaxy S20 a good phone?

Depending on how much storage it has and the price.

If I were you I would go on backmarket if you aren't already or facebook marketplace and go for a s21 instead or a s20 note since those are worth the base s20 is alright but most opinions favor in going to s21 or s20 note instead of just buying the base 20 since they couldn't find a legitimate reason other then camera specs to switch from a s10 to a s20. But is just my opinion and I would do more research just in case cause you don't want to regret buying a phone I hope this helps :D