Congrats. Now go to www.ruger.com and stock up on 20 round mags for 29.99 while you can. They are the only truly reliable 20 rounders available. They are backordered now but will honor that price until innauguration day and will fill all orders (according to their website). They've actually switched back and forth from backordered to available several times now. Only other mags to trust are the promag 20 rounders (available at academy for 19.99) I'd stay away from the 30 rounders personally. This is based on my experiences only, YMMV.
Speaking of ammo, my mini shoots the monarch blue box from academy perfectly. Stinks something fierce but is accurate and reliable. It's $5.29/box of 20 if you can find any and is laquered steel cased ammo. Thats what I've been stocking up with.