Help New here.

Went to Wal'Mart last sunday and bought two mountain bikes, on for me and the old lady. This is so that we could go down the bike path with our son, he's using training wheels so we figured these bikes would keep up. Well figured wrong. I have to say that I'm only thirty years old, but the sure as he@@ don't make them like they used too. I had bannana boat seats and double clamp goose necks and ten speeds, all were fit together out of what I could find, except for a few birthday pressents that was actually replacing stolen bikes or lost bikes. I just begun edumactin myself on this new bike scene. Both those Wal'mart bikes are back at Wal'mart now, ready for the next victim. Huffy used to make good bikes, and I'm here to say some of there stuff is pretty good still- I think. I got an aluminum elipse with shimono 21 speed shifting and suspension forks. It's working real well, I adjusted everything to exacting tolerances, eyeballed it all real good. It goes down the road fine, real fine. There may be some things to upgrade on it, like put some road tires on it, true the rims etc, thats' what I'm asking help on. Now I'm going to start riding more to try andlower my Blood Pressure! If'n any of you can give me some suggestions on cycling for better fitness (out of shape, a little fat and tired) or some aftermarket pieces make this bike last awhile, I'd really appreciate your input. If you can't stand I like my Huffy, I got a sense of humor too, recommend a bike for 5 or 10 mile rides that would leave little to be desired. I don't think I'd ever pay more than 300 hundred for one though, maybe somethings I could throw some upgrades on over time. I'm no racer, I don't go downhills or do tricks, just want to get fit and work on the bike as little as possible. Asking to much probably, Thanks for your time.