FunC exists since the very beginning of TON, and Tact 1.0 was released in March 2023 (less than two month ago), so it's just very new at the moment, and it's natural there are not many tutorials yet.
Speaking of the limitations: currently Tact is still undergoing reviews and security audits, so if you are developing something that holds a lot of money, for the time being it might be better to use FunC (or to use Tact and then audit the FunC code that Tact compiles to).
But for the learning purposes you can already freely use Tact. One of its goals is to lower the entry barrier for newcomers to TON, so it might be easier for you to use it than FunC (although that depends on your previous background).
And if you need learning material, I suggest the website tact-by-example.org.