[slink182]

OK, what you want is silicone spray lube for your magazines. The mags may just require a break-in period (BBs probably binding at the U). Shoot a short spritz (like, 1/10th of a second) into the magazine from the feed lip, preferably with the plastic directing nozzle/stick shoved into it. Get a 5-6 mm dowel and work the spring inside. Do this 2-3 times, then fill and empty the magazine several time to ensure the spring and the magazine internal walls are lightly lubed.

Don't use thick lube. It'll only gunk up your magazine and play hell with any loaded BBs (and hopup and barrel once you start shooting). Avoid using liquid lube - it won't apply evenly and may pool.

Check your hopup. Turn it down to zero/off and look down the barrel - if you see a bump from the hopup rubber, it's swelled and you'll need to replace it. Otherwise, turn up your hopup until you see the bump and run a few test-fires.

If your barrel's very fouled, pull out a 0.22 calibre cleaning kit, wrap/fit a swab, apply some light silicon oil, and run it through the barrel a few times (hopup off, or just deep enough to clean the barrel but avoiding the hopup). Run as many swabs as necessary for it to come out clean.

As you are new, just use the NiMH batteries. LiPo's have their own pros/cons. You can always move into LiPos as you gain experience running AEGs and your comfort level with them increases.