Don't give up! I actually never composed any songs in my life so most of what I said probably wouldn't work anyway…
I'm sure you can make some great lolicore if you put your hearto into it!
I guess you could either start with the cute
samples and build the song around those or make the song first and add cute
samples where you think they fit!
I think most people start with the cute
samples though and then just remix a song from the anime they took the samples from! That sounds like a good starting point for me anyway.