I'd say figure out some projects that let you get familiar with different basic data structures(stacks, queues, linked lists, trees, graphs, hash tables etc), w

I'd say figure out some projects that let you get familiar with different basic data structures(stacks, queues, linked lists, trees, graphs, hash tables etc), what they're useful for, and some of the basic algorithms that are useful to know for each. A decent one for getting comfortable with graphs off the top of my head would be something along the lines of a peg board. Users can attach each peg to any other peg, and once you create a closed shape it fills the shape in. It would give you a good understanding of graphs, detecting cycle etc, and is not a trivial thing to do.