best experiences as a scout was when my dad (who was in the same situation you were in) needed to come up with gear for a river trip. So he got us some sleeping bags (he did get good ones as we would use them later) and then used a couple of cheap tarps for a tent. At each camp, we had to use the terrain and figure out how to make our shelter. To an 11 year old that was an awesome and memorable experience, far better than any expensive Springbar and only $20.
If you don't want to deal with that, Walmart will have some cheap 3 man tents, get whatever.
If you plan on camping for awhile, then there are a plethora of gear choices that are quality.