I'm 47, wife 37, boy 3.5 and soon to be girl add on girl in a few months. We bought ours last year and have been out about 5 times. I will be fully retired in 3 years. From everything I have learned over the last year I'm glad I bought it now. Our intent is to travel with the kids a lot over their summer vacations from school. It's still a learning process, heck I back it up yesterday and forgot to unplug it from the house. No damage, just pulled the cord from the outlet. But it reminded me that I still have to get in the habit of checking things before I roll it out. I have warning straps for my steering wheel that I bought and only seem to use when camping. They were a must have after I broke my 2nd tv antenna. Things I never thought about when before buying. I wanted a class A. Never thought about a tow car. But it's something I'm seriously thinking about now as we are often stuck at the camp site and never get to see the sights outside of it. Towing a 5th wheel in some states do not allow for people inside. Was a major concern for us as the wife wanted the "experience" right out of the driveway. The next one I buy will have certain things in regards to appliances that I want. IE: I want an electric water heater. Our current one only runs on propane and heats up during the drive. But I like the option of not having to use propane in the winter months. If I'm at a campground, I'm already paying for electric and would prefer not to use my propane for something I'm already paying for. You also mentioned purchasing a truck to pull the 5th wheel. You might need a heafty one. They can be costly. Might be a better option to get a class A and tow a smaller car/suv. I have seen some pretty scary accident videos with 5th wheels and people not knowing how to tow correctly. Since you don't know much about trucks I figure you probably don't know much about towing a 5th wheel either. That's a whole other animal. I'm not 100% sure but I think towing a small car behind a class A would be easier then towing a 5th wheel. Again not sure on that.
Layout is a big deal. If you're going to be spending a lot of time in the RV layout will come into play big time. I have been seeing a lot of RV's now with TV's in the kitchen area and can't help but look at the seating. Much of what I have seen looks like the viewing would not be that great. Also large slide outs. They look great when they are open. But I have seen some that have 2 couches facing each other. When you close the slide outs there is very little room to walk between them (class A models). Another thing my wife and I don't like is the dinette seating. We prefer the booth style. It's a personal preference. We just don't like the individual chairs but we can see the benefits of being able to move the chair to adjust your seating to the table. Look long and hard at the layout, envision people in the RV and how they might be moving around, where they might be spending most of their time and how the layout is going to be affected. Sorry for the long post. Hope you can get some advice from it.