There are several great websites that cover battery chemistries snd their requirements in great depth. It’s beyond laborious to re-write them here over and over again, especially as there is a “sticky” at the front of the forum leading people to some of them, not to mention using the search function on the forum. There are literally hundreds of posts covering battery care and chargers. Spoon feeding is fine for the one being fed but awful for the ones holding the spoon.
Charger info can be found quite easily using the search function. Many are available that will charge up to 4 batteries at a time. The secret to obtaining a good, reliable charger is to avoid buying the cheapest ones available on eBay and Amazon. They don’t last, can burn themselves up, and are frequently not accurate. For a good “starter” charger than will handle two batteries you can visit Yuneec and look at their A-10 charger, or pay a little less and obtain the same one from Hitec RCD under a different name. Hitec is the actual maker of Yuneec’s charger. A visit to the Hitec website would provide quite a selection of different chargers.