I consider my sailing experince level as to be a newbie. I have only sailed Lasers and Hobie 16's and that was ten years ago. So whatever I say can be taken with a grain of salt or an honest analysis.
I am currently waiting to buy my first sailboat too but I'm quite concerned on what I can do with a 24 foot sloop. When learning to sail back at the age of 27, and that being on a Laser, I almost said "the hell with it". I was being taught by people that had a lifetime of experience of sailing and cruising but the sharks and the current that swept through the atoll and the sheer sensitivity of that little boat almost got the best of me. The required us to learn on the laser before we were allowed to get the hobie. As far as I was concerned the hobie was like flying a kite and the laser was like jumping in to a rocket ship without any flight training. Anyways, I eventually got the hang of it and miss sailing those little rocket ships. I was told by those that taught me that if I could sail a laser I could sail anything. We'll see, as I often wonder if learning to sail a laser is as hard for everyone as it was for me. My point being, it's one thing to camp on a small boat at the dock, but sailing in in the ocean is a whole nother ballgame. Not that it can't be done though.
The boat that I am purchasing tomorrow is a 24ft S2 sloop. Now, I will be mostly contained to an inland lake but I know myself and know that I will do everything I can to broaden my sailing area. At 24 ft. I think for me would be about the smallest I could stand. Being alone would leave plenty of room for supplies and a little comfort but I have a wife so sailing alone isn't an option for me. We could probably handle some gulf coast cruising but that'd be our limit. But that's just us and what I think my experience could handle.
The bottom line is learn to sail first. You will find that the experience will put things in to perspective. That being what you can do, won't do, or shouldn't do. You will also find that the ocean or large expanses of water can be quite daunting. I've been out in the Pacific on "nice" days that had 30 foot swells. Yeah, it was kinda fun but I wasn't out their alone. We were on a fishing boat with the land in sight but I decided then ad there that it was not something to take lightly.
Good luck and keep us posted.