I have a 10 gallon tank that has no CO2. I'm growing rotalla and micrathemum in it. It has 2 old 15 watt GE Chroma 50 bulbs over it, but everything is fine. The plants are quite a bit leggier than my 29 with CO2 though.
If you don't have a lot of light, you can afford to start slow. You won't be growing any light loving plants like glosso, but a lot of java ferns, java mosses, aponogetons, etc don't mind having lower lighting levels.
Later as you begin to feel more confident you can ramp things up a bit if you feel like taking on more challanging plants.