In the past I’ve set up my own gears on my 3×9 speed hardtail and it’s been fine. Now I’ve changed to 2×10 is it worth getting a bike shop to set them up for the first time as the tolerances between gears are different? The new setup is full sram xx and not sure if this makes any difference, can anyone help?

Should be just the same process 🙂

Same principles apply on the rear, so if you can setup 9 speed, then 10 speed is no different.
Front chainring is a little different with the barrel adjustment for a double, but its not difficult.

Triple setup is trickier if anything in my experience, but if you can do 3×9 then 2×10 should be fine.