Any idea on how I should start?

[Spark]

You see, I'm new to producing music. My technical skills suck and it all seems complicated. I know how to use LMMS a little. I can play the piano and the guitar. I can compose instrumental pieces. I know a bit of music theory. Any ideas on what I should learn and what I should strive to do?

[Freewave]

Well you're on MLR because hopefully you want to make music about MLP. Get inspired on how your song will tie into the show (something that ties into a character or an episode scene). A lot of people forget that they should look to the show for inspirartion first and just go for an instrumental and stamp on a pony name or image afterwards and that's likely the wrong approach as it carries no emotional or musical ties. Once you have that concept it should be much easier to figure out what type of a musical piece you want to write.

I would read this thread
viewtopic.php?f=13&t=2341
so you realize what a steep learning curve you'll likely have being new. No point repeating the same thing to every new musician who joins.