There are tons of Marinas all around the lake. There's a bridge crossing the northern part of the lake that is too low for sailboats so make sure you're not talking to any marinas up there (let them know it's for a sailboat). Some of the slips are private small little places (like where I keep mine) and they're less expensive but are slim on the dockside services. King's Point and Holiday Marinas are pretty big, there's also Morning Star. There are a couple yacht clubs, but membership is STEEP (depending on what you're looking for). Any of the Marinas you contact could most likely recommend a place to launch your boat once it's brought into the area. I'd recommend staying on the east side of the lake as that's the I-77 side with the easiest access to tons of marinas, west marine store, tons of other shopping and restaurants (Mooresville and Cornelius). This way if you're coming from Charlotte or from the north access is pretty easy. Otherwise you can add 45+ minutes to your drive if your boat is on the west side and you're coming from the east.
I'm not familiar with Marina Shores (it's right next to Holiday Marina), but it's near the Rusty Rudder, which is a great lakeside restaurant with sail-up slips for lunch
The area is really quite nice and I've found folks in the area friendly and helpful. You'll see the lake is well established with lots and lots and lots of high end homes shoreside all around the lake. Most the time I just see people fishing or slowly cruising along in their motor yachts, but when the wind picks up sailboats abound! I'm sure you'll like it. I have a 27' on the lake as well and I feel like it's the perfect size for the lake. Anything bigger and I'd probably be starving for more wind. But it's large enough to be comfortable and gunkhole and take the kids out on the water!