You'll likely be better off getting new arrows anyway, the spine of them may be too weak for the increase in draw length you needed to fit you vs. the previous owner.
Make sure to talk with the shop about what new arrows you'll need, they will be able to recommend the proper spine arrows for your draw length, draw weight, and how heavy of a tip (broad head or target) you plan to use.
They'll need your new arrows made before they can paper tune the bow to them, won't do you a lot of good if they are tuning it to the arrows that came with it that you don't plan to use.
A good arrow rest, wrist release, peep, and sight will get you shooting decent with practice. A stabilizer is nice, but not necessary if money is a bit tight.
If you've never shot before, now is the time to watch a few youtube videos about proper form, before you develop bad habits that will need changed.