I've just been through a similar process, as a beginner, and I've been to a dealer to look at the boats. He inflated a SIB for me and my wife to get a feel of, and brought out a couple of engines for us to lift etc.
I also wanted a boat that I could pack away and put into the back of my car.
The point is, I'm 46 years old and not unfit. We found that the 2.8m boat with a SIX hp Mariner on it quite a weight to manhandle about, we could not lift it (to carry into the water) with the engine on, and would need wheels to launch it.
That's the 2.8m Zodiac with a little 6hp Mariner outboard! It fitted into the back of my small van without problems of course, and the engine went in OK (although surprisingly heavy) Anything bigger I think we would be looking at a trailer.