Ok, here is a quick tutorial:

Step 1:

Copy Peter Levels stack:

https://www.nocsdegree.com/pieter-levels-learn-coding/

If he serves hundreds of thousands of monthly users and makes a million a month with a single VPS, you certainly won't have scaling issues when you start out or just have tens of thousands of users.

Step 2:

If you really scale beyond that, resist the urge to bloat your stack. Think long and hard about every piece you add to it. Really understand each piece you add to it. Don't fall into the trap of paid services. Don't fall into the trap of "best practices".