A few responses to your initial questions:
From your description, the tent sounds like a double walled tent, which is fine. In fact, many prefer a double wall because it tends to deal with condensation easier. Folks on this forum tend to go for the single walled tents more than most, in large part because they're lighter, but that doesn't mean there's anything at all wrong with double walled models. They comprise the majority of tents out there.
Non free standing is also not a problem. Again, most tents are not free standing, and it's pretty much the norm to need to anchor tents down with stakes in most camp sites. There can be spots where the ground doesn't lend itself to that, but they tend to be in the minority, and you can usually improvise something in those cases.
I'd double check the tent's instructions to make sure it requires seam sealing. Some tents have the seams sealed by the manufacturer. If not, then it's important to seal seal them. I'd also do whatever I can to test the tent before taking it out when there's any possibility of rain to make sure it is water tight. Nothing will spoil a trip more than a leaky tent.

All that having been said, if you're just starting out and trying to see if backpacking is for you, there's nothing wrong with a moderately priced tent from a big box store. In the long run, they don't tend to be as well designed or made as the name brand products, many of which you'll hear about on a forum like this one and others. But if you get into backpacking, you'll learn more about your needs and wants, and will be able to make a more informed decision and commit to a better, possibly higher priced model based on more information and experience.

I'd also recommend you pick up a intro book on backpacking. Ones by Colin Fletcher and Chris Townshend come to mind and there are others. They'll give you a good introduction to all of the gear you'll need with explanations of the basic design features, choices and trade off's of each. Most gear is a compromise of various features, and often the best gear for you depends in part on the type of use and conditions in which you'll be using it. So a good choice for one person isn't necessarily a good choice for another.

Hope that's helpful.

Gerry Magnes
Schenectady, NY