Samsung Galaxy Tab — How do I stop having to sign in constantly?

I've only just bought my Galaxy S8, but it's driving me nuts having to keep signing in. I only have to stop using it for a minute (or less) when it asks for my password again. I'm beginning to wish I'd never bought it.
I'm writing this on my desktop PC as I wouldn't risk it on the tablet in case I had to start over again.
If anyone can advise me on what to do, I would be very grateful. Thank you

Thank you for your help. I have set up a Samsung account, but only this morning. It hasn't appeared in Settings>Accounts and backup, though. Should it?

When I open the tablet (even if I've left it for just a minute or two) I have to put in the password (the one I made for the tablet, not my new Samsung account password).
It's very annoying to have to do this every time. .....On my desktop PC, I only have to put in my password when I boot up, and if I leave it for a while, it goes to sleep, and when I wake it up, no further login/password is required until the next boot-up. So I don't see why the tablet needs a password each time you leave it for more than a couple of minutes. If there's a way around this I'd really appreciate knowing. Sorry this is so long.

Thank you again for your help, which is much appreciated.

Is there anyone who has a clue how to stop this? I really would appreciate some advice. Thanks. ?