Kim sums up most of your worries.

On the other side, I remember my first zen cart. I basically threw a dart at ecommerce packages and that dart landed on zen cart.

At first it seemed overwhelming. But I committed myself to spending one hour a day for seven days in a test enviornment.

Day one...I don't get it. Is my hour up yet?

Day two...I remember that, don't get it. It's been an hour.

Day three...Oh I get it!

Day four...making progress

and so on.