Advice about which tech stack to use in a social media app

I want to make a web app that kind of has the aesthetics of Instagram and Pinterest combined if that makes sense. The main part is this:

• Users can upload content like food or their pair of shoes and you include a link to where you got the stuff from (can either be the store name, in which case it tries to find the one nearest to you or just open up the wiki page for it) so you can just order it easily.

• There are no passwords. You have a public key on your account and a private key on your device. If you want to add in new devices you just scan a QR Code

My question: What tech stack should I use? Which Language should I use? Which cloud provider should I use? Is there a way to avoid SQL coz I hate the syntax?