Low powered, semi-realistic fights are not a bad way to start. A few things. We tend to use a version of T1 Eden era as our platform for fighting. If you don't want to use that you should hash out the rules you are planning to use as it cuts down on arguments and keeps the fight going smoothly. Secondly, as Vordy stated, having characters that are of the same "relative" power is a good thing, so were I you, I would have Vordy give each character a once over. He has experience, understands how things should balance out and is a good guy overall to learn from.

Thirdly, competitive fights are different than the run of the mill fights in a normal role-play. Your ability to write clearly, concisely and describe your attack without ambiguity are tantamount. Also think of it as a chess match and try to see the fight and plan several moves ahead. 

Good Luck