Which tools should a tech stack include when building a social media website? [closed]

Sorry this description is so long, but I wanted to make sure I clearly outlined my project so that my question is easier to understand.

I'm working on developing a social media website and I've been very overwhelmed in my search for the "perfect" tech stack to use. I'm comfortable with coding once I have the tools in place, so I don't want to hire any developers if I don't need to. For front-end, I coded in JavaScript and CSS using Reach with Next.js, and I'm pretty happy with my progress. However, when looking at first steps for back-end development, online articles make it seem like this probably wasn't the best option for a large-scale project like a social media website that (I assume) will require a MySQL database. Based on my current understanding, MongoDB is the only database I can use if I keep following the path I am currently on, and a lot of resources have recommended against MongoDB for social media websites. Ideally, I would be able to keep my JavaScript and CSS code, but if using something else is a necessary change in the long run, then I am definitely willing to make the adjustment. I also noticed that there seem to be "host" platforms (AWS, Digital Ocean, etc.) that support certain types of stacks, but I'm a bit confused about how those come into play if I am able to customize my tech stack.

Like many other social media platforms, this website will have user profiles, friends, posts, likes, comments, notifications, DMs, linking posts with other social media platforms, etc. I am hoping to get an initial version of this website / MVP out soon for user testing, but my goal is to eventually have a lot of users join (and probably implement more features), so I definitely want to account for vertical and horizontal scalability. Also, while costs will obviously go up as this (hopefully) progresses, I don't necessarily need a free/low-cost option right now if a paid version could be a lot of help, even in early stages. Please let me know if any additional information would be helpful, but I am generally hoping for advice on how to choose the right tools that seem to come up in every article about choosing the right tech stack: programming language(s), server-side framework(s), OS, database(s), API, web server(s), and content management systems. And if that isn't a complete list of what my tech stack might need, please let me know what I might be missing - I really appreciate any advice given!