Get a Clean Start
You cleaned your duck gun at the end of last season didn't you? No? Shame on you. For this waterfowling season you need to do a maintenance check on your duck gun. Duck hunting is often a dirty business and is tough on guns. If you start out with a cruddy gun, you can almost count on malfunctions, usually at critical moments, while shooting. With modern ammo, bore corrosion is seldom a problem. It's everywhere else that gets gunked up--particularly the action.
Strip it down and clean it out. Use degreasing agents to soften up gummy deposits. Dig into tight spots with an old toothbrush and pipe cleaners. I sometimes use an air-pressure hose to really blow things out. Autoloaders are quite reliable when properly maintained but are particularly sensitive to fouling in their mechanism. It's not the autoloader's fault if it quits autoloading because its critical components are filthy. When the gun is clean, lightly lubricate it and you're ready to go.
The Best RiflePicking the "perfect" deer rifle for a youngster or for a small woman who is a novice isn't easy. First deal with the size thing. Many manufacturers list "ladies and youth" models. These have shorter stocks and sometimes shorter barrels to fit smaller-framed shooters. However, on the question of caliber, we must be careful. We want a cartridge powerful enough to reliably take a deer but without serious recoil consequences. The old, reliable .30-30 is a good short-range choice. It hurls a sizable slug, produces moderate recoil and works well to 150 yards. Novice hunters would do well to restrict their shooting range anyway until they upgrade their skill level.
For longer range shooting, some go for the .243/6mm, but their 100-grain bullets are marginal for deer-sized game unless perfectly placed. The 7mm/08 Remington, 6.5x55 Swedish and the new .260 Remington all shoot 120- to 140-grain bullets along flat trajectories without producing severe recoil, and all are powerful enough to take deer effectively.