It is important to play with other people. If you can't afford a bigger amp at the mo you will just have to play quietly, which isn't necessarily a bad thing anyway.
Even if you can't find other musos who are in to your kind of stuff, just go for it. It will all be good experience.
In the early days I couldn't afford my own amp. But the guitarist had a woolworths combo with four inputs, so I went in to that, along with two guitars and the vocal. Sounded absolutely atrocious, but we didn't care it was just exciting making some noise.
When I did finally get my own amp, our manager (the guitarists mum) said that I really ought to play the right notes now that I could be heard.
Sorry, waffling a bit.
Bottom line: Don't put off doing it because you fear you haven't got the right kit. Make the most of what you have got and just enjoy learning.
Best of luck with it.