Magento set up

I am trying to get a magento 2 site up and running but nothing seems to be working. I tried updating the footer, the phone number, etc...also I've created many new categories and nothing is showing up. I need to know how to properly bulk edit products as I've loaded 1200 but I need to change tax and categories on each of them, but magento doesn't have a way to do that as a build edit, so what is the next step? Please let me know if you can help me fix these things. I also have about 10000 more products coming so the most important thing is to be able to bulk edit and make sure all the categories show up correctly in the theme.