1. Don't use the default movement. It's buggy and most of us can tell right away, and go 'ewwww'. Search the articles for tuts on custom movements.
2. Avoid Mario clones. If all you can do is run and jump on enemies and collect coins, your game is going to be boring to most people. Something completely unique is ideal, but all you really need is *anything* interesting to do above the usual stuff.
That's right - start small and build up. It's tempting to try and do something ambitious right away, but you need to treat it like learning anything else.
I tried looking in the articles for custom platform engines and they all seemed good, but i couldn't follow the instuctions because they were too brief for my amount of knowledge on this program. The only bits of programming i do know i learned from my next door neighboor "saven".
It would also help if I could open the .cca files. When I try it gives me an error telling me I'm missing extensions. Do I need the full version for that?