It helps to know a few more details such as how big is your tank, how much live rock do you have, how long has it been set up, how many and what types of corals do you have now and also plan to have in the future...

You mentioned getting some stars and it sounds like that would be one of your first corals? If so, then right now you should be good just focusing on water quality (clean water with low nitrates and no ammonia or nitrites at all), do regular (2 to 4x / month) water changes and that will replenish the small amount of minerals you will need at first. You don't really start to deplete the minerals in your water significantly until you start putting in LPS and SPS corals.

Don't be in a rush to buy a lot of products, no matter what your LFS is recommending. Just buy salt instead and do another water change. (We've all been there!) Slow down, read more, and test your water for anything you would consider adding as a supplement.