Legoland is still about two months away from opening,I would be surprised if there's no shuttle available from somewhere in the tourist areas,whether it be somewhere on International Drive or the TTC in Disney.As the opening gets closer keep an eye out for info on a shuttle.Legoland is also a lot further from Disney at least close to a 45-60 minute drive,Sea World is about 10-15 minutes away and a lot more accessible whether it be a cab,the mears shuttles or even public buses which will take longer but will get you there.