LinuxMusicians

Greetings I am new and requested help. I have two questions. To use LMMS which distribution is the most recommended?
I will work a lot with MIDI sound, with LMMS eliminates the problem that is in Windows having to replace the virtual synthesizer to get more real sounds? Clear depending on the SoundFont.
Thank you for your help.

I recommend reading this first:
https://libremusicproduction.com/articl ... stribution

But I've got to warn you: LMMS won't sound better on Linux, or worse .. it will sound like LMMS

I will recommend to use it with Ubuntu Studio.
Its my recommendation for out of the box Linux Audio experience. And LMMS is included in the distribution by default. Its a great place to start your journey.
Although KXStudio repository provides more and up-to-date applications, it sometimes can be a hit and miss. The approach is quantity over quality in KXStudio. It can be heaven for a old time Linux user, but a true deal-breaker for a relatively new user.
As for which version of Ubuntu Studio to choose, i recommend 17.10, which you can upgrade to 18.04 LTS around the mid 2018. Although 18.04 will be released on the end of April of 2018, you should give it a little time to refine the possible initial hiccups.
PS: Welcome to the club. Enjoy the ride!

I would say that for using LMMS distro or even operating system does not matter. It works everywhere.