At 84, do whatever you want to do, whenever, and however much you want to! By the grace of God, hope I'm still able to fly at your age....

Regarding gas, if you haven't been around it much, there is a learning curve involved. The DLE 20 is a sweetheart once you get to know it - but it's not going to behave like a glow engine. You'll need some patience with it at first....

If it's a cowled install, pulling that off until you get good and used to running it will be a huge leg up.....