Those lipos have a 1C charge rate so 5A is max. Lower is fine but I would recommend 5A. If you go too low and your charger has a time limit, it may not fully charge. (Because it will time out)
There is also another spec that most people don't pay attention to which will tell you how many cells make up the lipo. For example a 2S lipo could be 2 or 4 individual cells. It all depends on how they are wired internally. This is where your 2S1P and 2S2P come from