I'm in the process of 'starting again', as i'm going from 360 to xbox one. The online loss is really sad but if you don't really try to get into it, and just download some toy boxes, 'you can't miss what you never had'. I agree with ElmoSTM about the 'expansion games', pick up the speedway crystal piece, it's a really fun MarioKart clone that you don't have to build in ( works in 3.0 ).
And your timing... I came to the party about 8 months ago, and I feel like I missed out on a lot. But you are in the perfect position to save a bomb. Earlier adopters were paying £15 a figure, so you're talking a couple of grand to collect all the figures and sets. Now you can pick them up from a pound each second hand. People are selling because they think the game's community will wither, and are jumping ship. This is the perfect time to take advantage of that and enjoy a really great game with fantastic toys.