For cleaning, well, there are as many cleaning products as there are opinions on the best. Me, I've tried a bunch: Breakfree CLP, Mil-com grease/oils, FP-10, Ballistol and a few others before settling on Gun Butter oil and grease. Just follow what the owners manual says, and don't over lube. I clean after every match or range trip, no matter what the round count.

Break in: I recently bought a Shield and M&P 9. No break in required or stated in the manual, unlike some manufacturers. Like someone else said, Just Shoot It!

Get some snap caps for dry firing and drills, definitely.

Be safe and have fun!