Database using Google firebase / firestore

I currently have a website that pulls a row of data from a google spreadsheet by querying the logged in user to firebase (on the website) with the matching emailaddress on the google spreadsheet. So it matches the email and then pulls the row of data changing items on the webpage with [login to view URL] text and variables for image urls. The website already has a fully working user sign up, login, logout functions and web pages connected to firebase. I want to move from using google spreadsheets to storing all the data in firebase. Step 1) logged in user needs to be able to create posts, each post should have a post text variable, post image variable, author image variable, author username variable, time posted, tie (min/ hr ago) calculation variable. Step 2) logged in user can comment on each user post, commented posts should have a total number of comments variable, total number of emoji interactions variable step 3) comments on user posts shoud be stored in chronological order, author of comment image variable, comment text, author of comment profile image should link, author of comment username should link to user.