Newbie sound font question

Hi,
I am using Ubuntu Studio and I am trying to learn how to use ardour in my road as a pianist amateur.
Currently I can record my electric piano using midi input , and for the sound I am using Calf Fluidsynth with FluidR3_GM.sf2 sound font.
I want to improve the sound of the piano. I was looking for others possibilities and I downloaded SalamanderGrandPiano and maestro grand piano . But I couldn’t find understable docs in how to use them . I tried to load the sfz file from SalamanderGrandPiano into Calf Fluidsynth and Ardour crashed with these error messages:
fluidsynth: warning: SDL2 not initialized, SDL2 audio driver won’t be usable
fluidsynth: error: Not a RIFF file

Please, if my question is very basic , give me some link or resource to study and understand what is the thing that I am doing in a wrong way.
Thanks a lot !

:cowboy_hat_face:

yes !!!
Thank you ! I was be able to install sfizz and load the Salamander Grand Piano sfz file.
It sounds a lot better
Thanks again !