abran, I would suggest first, there is a wealth of Bonsai related material on the web. Take some time and do some reading and studying first. You will get a wealth of info on different trees and their culture. Especially to your area, where you can keep the tree, how to handle it during winter, etc.

Most of the time a 'home center' is the worst possible place to buy a tree/shrub of any kind. Try a 'real' nursery they will provide you with some information about the tree as to bonsai and some people there do care.

Bob

This may sound a little harsh because you're new & don't understand much about bonsai yet, but it's not meant to be. The best advice I could offer is to learn how to keep your trees alive. If you're not willing to invest the time to pay those dues, your efforts will end in frustration and you will soon lose interest. Focus your primary attention on how plants work (their physiology), and on soils. Therein lies the the key to a good start. The other aspects, including the artistic component can follow the basics, but you'll naturally absorb much in these 'other' areas as you progress.

Sunset Publishing puts out an excellent text for beginning aspiring artists. The title is simply "Bonsai". Early editions of this book are poor, but the one by Susan Lang, published in '03, ISBN #0-376-03046-1 is very good and presents a good overview.

Al

Hey, Abran, welcome!

Short answer to your question is, yes...but with some caveats.

First, as Bob said, home improvement stores won't have the best plant material.
And what they do have will most likely be stressed from bad soil and potting
conditions. So, if
you can, go to a nursery proper. However, even at a nursery, you might
encounter plants that are root-bound...if the roots haven't been tended
as the containers have been sized-up.

Secondly, as Al says, you need to understand plant physiology and soil
dynamics. Al's Threads in the Container Forum are invaluable resources.

Thirdly, most bonsai are grown outdoors.
Smaller containers are more affected by hot and cold extremes. So, where
do you live? What are your options in terms of plant hardiness?

Finally, be advised that High Summer (in north America) is not the time to be
disturbing roots; for instance, planting or re-potting trees, et cetera.
If you buy a plant now, it might be best to keep it in its pot, in a mulch-pile
perhaps, until next Spring.

Josh