Choosing a suitable SQL service provider

I’m not sure if this is the right place to put the question, please advise me accordingly.

So I was working on a job search platform that aims to be released on Wix, Android and IOS. I was trying to find the best fit database service for storing and communicating information such as company info and job info between these platforms.

I’ve read some documents on SQLite, MySQL and PostgreSQL for their pros and cons. What I want to find out is will the cons of these databases affect the performance severely, like the constrain of not having multi-user communication for SQLite, slow data modification and concurrent retrieval for MySQL, resource-intensive processes for PostgreSQL, and any other problems that I don’t know of yet. Is there any workaround for these problems or is there a norm in the industry that there’s the best choice of SQL service for this scenario? Any additional information worth noting is also appreciated since I would like to avoid any troubles if possible.