Why is it so hard to sign in? It shouldn't take 10 minutes of wondering around the site to sign in.

to sign in, enter your username and password.

you may have to enter the code sent to you for two-factor authentication.

To sign into what?  Have you started a 2020 return or need to start?  Start an Online return here,

https://turbotax.intuit.com/personal-taxes/online/

Or can't you find your account?  It's common to end up with multiple accounts. First LOG OUT of whatever TurboTax account you're logged into right now. Then use this TurboTax account recovery website to get a list of user ID's for an email address. Run the tool against any email addresses you may have used
https://myturbotax.intuit.com/account-recovery/