Off to a great start! I can't tell for sure but make sure you only bury the roots of the anubias and not the rhizome also make sure the java fern has rhizome above the substrate. Rhizominous plants need light on the rhizome.
I think your root tabs are a good idea but you can easily dose other ways. You just have to figure out how much or liquid or dry ferts to add for your tank size. There are online calculators to help. I would suggest going to the fertilizers section here and looking around.