Help with Adventure To Fate - Quest For The Future

Hello. I am playing a game called Battle Arena and everything is accessible. But there is one thing I cannot do. I cannot seem to be able to do a battle and I would need to get instructions on how I do that. Thanks.
This seems like a very good game and I like it but I just cannot figure out how to battle.
If we say I am battling a sewage leech, it says for me to tap the leech and I cannot find it and need to know where it is situated.
Navigation goes easy and I have figured this out. Things are a bit confusing with multi layered screens but I think I have gotten the hang of that part. Thanks for any help.
//Sabrina