I just purchased a Rem 870 12GA 18", it will be used for home defense and shooting in the desert. I've never fired a shotgun before, how often do you need to clean it? All I've ever cleaned are Glocks and revolvers, is there anything tricky or to look out for with the 870? Also it has a bead sight, if I were to get a ghost ring what would you recommend. I'll be taking a tactical shotgun class which has some 50- 100 yd slug shooting so I understand I'll need a ghost. Thanks