have fun
start with a small load to get use to it. if you are using pellets, try 100grains. If powder, then start with90-100grains. After you get use to it, then step up to the big loads if you want but 90-100grains will do the job out to 100yards easy

I like 100grains of triple 7 pellets, but recently I just switched to the blackhorn 209 powder and a 115grain load. Grab some different sabots to try. I like shockwaves but I hear SST and many others do the job also. Barnes makes some very good loads also.
Goodluck again and happy shooting.. remember the more you shoot, the better feel you get for your Ml'er. Also, try some freehand shots without a rest after you get it sighted in because 50% of the time you may not have a solid rest to shoot from in the real world
after you are done, take the time to break down and clean the gun. Some people slack on that part and wonder where missfires and etc come from.