Brand new - lookup help

[Thornzee]

Hi, so I have what I hope is a very basic question. I have a single table with two columns (account name and account code). I would like a user to simply select the account name from a dropdown and the account code will populate in a form. Is there a way to do that?

If possible, I would then like to try make it bi-directional. Where a user could select either the account name or account code and the respective other would populate.

Brand new to this. Any help is appreciated!