Another thing you can do to keep their water clean, is get a turkey baster or something similar & remove any uneaten foods between feeding.
the turkey baster, as you will learn is one of the most valuable tools in a fish keepers tool box.
and don't feel so bad, i worked with mystery snails and guppies about a year ago and had not a clue what i was doing, but i learned along the way and found a valuable resource in the knowledge of the people both on the forums and in the chat. always willing to share their knowledge and if they don't know help find you links so you can educate yourself.
please do not let a few negative comments discourage you, because i can see you growing into a great betta breeder
the turkey baster is a godsend for fishkeepers, do you know I dont think i've ever used one to baste a turkey? lol