Hi Recca and welcome to the Org!
No rush in choosing a role, however think of it like “what role do I like spending more time doing in SC?”
That should help you answer the role question, and even then it’s not exactly set in stone as you do have the option to change role if you like 
If you have any further questions about the game, etc drop a message in the appropiate channel in Discord and we wil reach out to you bud.
Welcome once again to ADI bud
TR0PHY