I'm trying to learn by myself sql, and the book I'm using (Learning SQL by Alan Beaulieu) uses mySQL. However, since it's all done from a command prompt, with no IDE, I thought it would be more useful to install MS SQL server 2019.
To import the sakila example database (from mysql website, composed of the files: sakila-schema.sql, sakila-data.sql and sakila.mwb) to MS sql server, I created a new database, accepted all the default values, and then went to import data -> From Flat File, but none of the columns seems to have been built correctly...
I feel completely lost =D
SQL Server and MySQL are different platforms. Think of SQL Server as Microsoft Excel and MySQL as Apple Numbers. They're similar, but you shouldn't expect to be able to use them interchangeably.
Converting a database from one platform (MySQL) to another (SQL Server) is very often going to be a non-trivial task. Depending on the specifics, you can probably find some tools that work in many cases - but almost nothing will be a general solution that works exhaustively cross-platform.
The good news is that figuring out why that tool broke can cause you to ask the kinds of questions that teaches you a lot about _both_ database platforms at the same time. The bad news is that this is likely to take a _**long** time_.
If you are final in your decision to try to learn in this way, I don't recommend using _any_ 3rd party tool. That will just give you a **3rd platform** (maybe even a fourth or fifth) to learn alongside the 2 database plaftorms you mean to be focusing on. Instead, work through the sakila-schema.sql and sakila-data.sql files section by section and line by line. This will likely teach you more about the target database than the source though as you edit and debug.
Alternately, consider using [AdventureWorks](https://docs.microsoft.com/en-us/sql/samples/adventureworks-install-configure) as your sample database for learning SQL Server. If you want to learn MySQL though and you just need an IDE, there's really [quite a few to choose from](https://codingsight.com/10-best-mysql-gui-tools). I recommend asking the friends or colleagues what they use. Failing that, you can always fish around [in chat](https://topanswers.xyz/databases?room=2) :-)