Just ordered a complete lower from. Psa for $189 for my first ar.

Is all I need a complete upper and then I have a complete rifle?

Yup, just make sure the complete upper includes a bolt carrier group (BCG) Some uppers are sold w/o bolt carriers.

You also might want a magazine or two

And check on the charging handle, some of them are missing those too.

Kinda funny what some shops consider as "complete"

Ammunition in the correct caliber is a must have also.

You'll want some manner of sighting on the upper. Perhaps a sling?