I have a large goal list if you want to poach it: Lucid Dream Goals - Dream Journals - Lucid Dreaming - Dream Views

You could find your dream guide. You don't need to attach any spiritual or religious meaning to it. It is a fascinating experience to conjure up something in a dream that is supposed to be wiser and more powerful than yourself and to try and learn from it. It is a good thing to look into.

You can eat something that is non-edible. It is pretty cool to see how your mind creates tastes and textures.

Instead of flying you can try free falling, it is exhilarating

There is no end to interesting things that DC's may say to you if you speak with them. But it is definitely something that you need to practice to get good results at. It is difficult to remember dialogue and they become more realistic and interesting the more you spend time with them.

Telekinesis is very fun and takes a lot of practice (like flying) to get good at. Same with controlling the elements (fire, water, wind, earth)

Becoming insubstantial and morphing objects/people is challenging and interesting

Try speaking a language that you really don't know

The most fun thing to do could be to try and make a DC reoccurring. Meet up with them in every dream and explore/have fun with them.

Then of course there are things like astral projection, OBE's, remote viewing, precognition, and shared dreaming you could explore and try to see if they are real for yourself.