Before buying a boat, I would recommend you get some time in sailing on larger boats first. Buying a boat is an expensive commitment, and if you're going to be miserably seasick, it might be wise to find out before making the leap.
It would also be a good idea to spend some time on some cruising sized boats so you can get a feel for what you're looking for in a boat. Galley, berth, salon and cockpit layouts can vary quite a bit.
Taking a good basic "learn to sail" course is also a good idea, as it gives you a solid foundation on which to base your future learning. A good book to buy is Dave Seidman's The Complete Sailor, which costs about $16 or so and is one of the best sailing primers I've seen in years.
If you've decided you want to make the leap into owning a larger cruising-type sailboat, as opposed to a daysailer or dinghy, then I'd recommend you read the
Boat Inspection Trip Tips thread I started, as it will help you determine whether other boats you look at are even worth going forward on, saving you the price of a survey on any boats that aren't worth looking at further.
As for gear on the boat, that depends on the type of sailing you're doing. A longer trip will require more gear and equipment than a short daysail. Going bluewater will require different equipment than coastal cruising.
Basics, for daysails and weekend cruises include:
Food
Water
PFDs
Jacklines, harnesses and tethers if you're singlehanding or going to be sailng in bad weather. See the
article I wrote here on this.
Handbearing compass
Charts and navigation tools—parallel rules, dividers, pencil
Binoculars
Foul weather gear
A couple of changes of clothes
An air horn—I prefer the EcoHorn which is re-usable and recharges by using a bicycle type pump
A whistle, knife, flashlight and strobe for each crewmember, preferably attached to their PFD—I prefer the small waterproof LED flashlights, like the Gerber Firecracker
Sunblock
Insect repellent
Sailing gloves
Good luck and I hope this helps.