I have wondered for long, if there is anyway to recover my private keys when they get lost or when I don't remember them. Someone advised me to use Gmail and store them as mails then I taught again, what if my Gmail gets hacked. Is this actually the best way to store them or is there any other ways I can store or Keep them safe?
Depends.
There isn't one solution that's safe for every situation. It is not possible.
Let's say you memorized your seed words... your brain can always go dumb and then boom you are poor.
Let's say you wrote them on a piece of paper. That piece of paper might get burned, might get lost... Your dog could eat it.
Let's say you kept it inside an USB stick. That stick might get broken.
What if you keep it in your PC? Could get hacked.
What if you keep it in a bank safe? lol
...
What if I do all of these?
Then you will have lots of targets which could be attacked.
In my own experience, you should do 2 of these. One of them should be your main preparation and the other one should be a backup.