You'll probably get a larger caliber pistol in the future, but for now, you go with what you have.
Use the roundnose bullets exclusively, you need penetration, not a blowup on a button, buckle, or bone.
CCI is reliable, burn up a brick and verify. Keep the last box of the brick for carry ammo, once you've proven the ammo lot.
I hate to say this, but your choice of the 22lr for defense means two things are crucial to your life expectancy in a confrontation: the first, obviously, is shot placement. The second, is reliability of your semi-auto pistol. You will require a second, third, or sixth shot. Practice clearance drills religiously, and seriously consider a revolver if you expect to rely on the 22lr for any length of time.