you'll need a few slugs, 5rd box should do, and some 00 buck. These will be for "zero" and patterning at reasonable defensive shotgun distance. The rest will be reliable in your gun field or target shot. Round count is still being discussed.
I'm currently running old school plastic side saddles on mine but looking to switch to the velcro on cards. I think that ANY reliable way to keep ammo with the gun will work.
ACT will again partner with Revere's Riders to present Pistol 145 on 23MAR at Lost Creek Conservation Club. This class is based on ACT's DP101. Check RR's website for detailed information and registration.
This is an excellent intro to shooting in a very low stress environment. Reveres Riders does a fine job with this class. And you might learn some history.