[timr]

If all you want to do is play around with molecules on a screen, check out PyMol.

But here's the rub: if you want to learn "bioinformatics", you're going to have to accept that most of the work is inherently not visual. I worked in about the most shiny, graphical part of biology possible (protein structure), and maybe only 20% of the work involved spinning molecules on a screen.

The real work of bioinformatics involves thinking very hard about problems that are deeply mathematical. The visualization part is strictly secondary -- though it gets the most attention, for obvious reasons.