Any of our smaller boats will get you on the water faster than building the Weekender or Pocket Cruiser. Which one you chose depends a lot on the type of sailing you want to do: The Triad is stable, slightly slower, carries a lot more gear or people, and can be motored or rowed. The Super Skipjack is faster, more like the Weekender in appearance, but but a tiny bit less stable than the Weekender (not maybe a big concern). The 3-In-1 is smaller, but simple and handy (Sail, Motor, Row). Don't forget the Mini-Cup, a very fun and simple boat, but just for sailing (same with the Wing-Dinghy, but just slightly more complicated than the Mini-Cup). The Weekender, Pocket Cruiser, and certainly the larger Vacationer will allow you to carry lots of people, stay overnight at some beach or inlet, and can open up a new world of funthey are larger projects though and will take time to get finished (the obviously will cost more as well.)
It's up to you. Pick whichever one looks good to you, both aesthetically and practically (financially too.) The key is to build the boat which really makes you excited!
The smaller boats are simpler, mostly because there are fewer parts. None of the steps in building a larger project like the Weekender is really hard; there are just more to get through. If you have patience, or perseverance, you could go straight to the larger projects if you like (especially if you get the 3 1/2 hour video which helps a lot if you're starting out). If you'd rather get on the water sooner, and get some experience first, try the smaller boats. Keep in mind that first-time builders with no previous experience building boats (some had never built anything!) have completed and sailed successfully all of the boats on our site, including the Pocket Yachts (the Weekender, Vacationer, and Pocket Cruiser).
It's quite possible to have a very rewarding and fun project with no prior boatbuilding experience!