Try reading through the Craigslist Ads to see how others are posting ads. No, there is no assumtion that a poster has the responsibility to provide things like a space. In fact, it was mentioned above that many musicians don't have a space and live in apartments in cities, etc. I see it mentioned often in CL ads that they don' thave a space so if others do, that's a bonus or they can rent a space to see how it goes. Hell, see if you or they have a friend that wil host you all meeting up and playing as a one time thing to see if there is any interest, then seek a permanent solution if there is. The nest thing you can do is list your e-kit, what you're into, what you're looking for, and that thing about the space. Don't be too apologetic or focus too much on things you are self concious about or it turns people off. Find a balance of that and letting people know any significant efficiencies in your level/abilities, but you don't need to say it all in the ad. Let the meeting happen and others to judge for themselves, or you just cut a lot of possibilities. I did that when I 1st started out, perhaps because I was too woried about wasting peoples time or that I wouldn't live up to some ideals I came up with in my head. Figuring that out and getting around that quick in life was a blessing.