How to choose the right sql + c# database for a project, there is a lot of information, without exact advice, is it difficult to choose?

Question

Database

I want to select\write\read\delete\modify columns, rows in a table, there will be large data size for web applications and win.
What is the best way you can recommend using the C language #
How to understand which is better, there is a lot of information everywhere, but I can’t put together an exact definition to start creating a project.
1) mc Sql server or sqllite or mongoDB or PostegresDB, RabbitSQL some other
2) how to use data information, trim large data for small parts and do search in multithreading, there was advice to use asynchrony, I think how to use better or how to best work. The goal is to create a database for a store with positions of about 50,000 products\articles\pages, tags, categories, how best to create?
split 1,000 rows into 50 bases to search for each column for a match or use one table, what experiments were carried out, what code is better - sqlite - just like one file - I think it won’t work, it will hang for a long time sometimes, perhaps, and also how be sorted so that the data in the database is constantly also sorted to facilitate search
3) What is the best solution for 1 part of the query, query by filters, multiple queries from multiple users for stores and NetWork RPG Game Multi Online world, for example, through winForm games\Unity , web games with quests and an online multiplayer world?
4) To choose the right equipment and the project was optimized as much as possible for recording and retrieving data from the database and displayed to users

Answer 1

Thank you, what can you say about the Azur account, for a free period for startups, did I understand correctly that you can get up to 12 months of free use of certain services or one service, have you used it?
Wouldn't it be bad to get access to use for the initial growth of the project for 1 year of free maintenance of the database on the Microsoft server or am I mistaken and frivolous in this matter and finding a solution to the problem, discussion? What can you say?

Answer 2

I have experience with MS SQL Server, worked also with MySQL and SQLite.
MS SQL Server is quite comfortable and handles large amounts of data well - I think it will suit you better than others.
The free version of Express up to 10 GB is fine.
You only have 50,000 products/articles/pages, tags, categories... - quite a small amount.
There will be no brakes, unless of course you create indexes correctly for heavy queries.