thanksIf you just want to use this as more of a learning experience, the 15w bulb will work as long as it is within 6700-10K so that it it beneficial to the plants.
As far as CO2, I wouldnt worry about it at first, just try at first without it and then once you get used to taking care of it, you could try a small DIY system possibly... really though, I wouldnt worry about this at first, there are many other things Id worry about first.
As far as ferts go, you can do as many or as few as you want. Dippys post at the top about starting up a planted tank really goes over it pretty well... obviously the more effort you put into it, the more the plants will benefit and youll get better color and growth.
Not sure where you are in Canada, but might be hard for you to get some plants and of course everything is a lot more expensive up there.