What to learn for building web app that pulls in rest api


I am not knowing what to learn for this project. I believe, like inventory management type program. here is what i want to do: (web based app)

  1. request restful api calls from Marketplaces like ebay and amazon, etc.
  2. display the data in an editable table.
  3. update and sync inventory to all marketplaces.
  4. would need inventory system to create the Main Products, to connect the marketplace listings

Right now this is what i would like to start with, I have other features i like to add later. I figure this is the most basic to view and go from there. Please let me know what programs to learn or if i need to.

i know a little bit of html css and learned some javascript but don’t know much of what to do with javascript.