Here are few Shazam combos that I put together. I'm sure there are more efficient and optimal combos out there but Shazam does decent damage without getting all fancy. Most of these combos involve burning 2 meters because meter burning his command grabs enable for combo extension.
These are pretty easy to pull off because Shazam doesn't have a lot of normals and strings that he can combo off of. At least as far as I can tell.