I have downloaded the lol pbe and I have tried to login as my account but that wasn't working. So I made another account and when I tried to login it still didnt work. Can I please get some guidance here?

You have to make an account on the pbe account making page.

Did u make a PBE account or did u just use your normal League account?

U can only make PBE accounts at the beginning of each month now.

they changed it so you can only make PBE accounts at the beginning of each month