I have an extremely irregular period...HELP!?

I got my period for the first time a month ago and am worried about it sneaking up on me. what do i do so i don't have a sneak attack? also when i try to put a tampon in, it hurts. i find my , angle the tampon upward and push it in. 1 problem it hurts like crap and when i walk it looks like i am waddling