Good job learning the piano. It sounds as if you're self taught, which is amazing. Keep at it. I was blessed to have parents who encouraged me to start young, but I believe anyone can learn.

In terms of making music more interesting with your current skill level, I'd first learn chord inversions (if you haven't already). For example, a C Major chord is C-E-G. To start making music sound more full and interesting, you'll want to understand chord inversions (first inversion which is E-G-C, second inversion, which is G-C-E). From there, practice spacing out these notes where your left hand and right hand plays a few of the notes (e.g. a second inversion chord where left hand plays G-C, right hand plays E-G). In this example, you'd essentially be playing a C/G chord in pop music chord theory. The point of this exercise is for you to start hearing music and melodies more harmonically so that you're not always playing the root of the chord in the left hand.

The second suggestion, if you aren't doing this already, is to train your hands to play different rhythms on the piano. When just starting out, most people end up playing chords in a steady 4/4 rhythm. Trying mixing the rhythms up, practice syncopation (putting the accent of a rhythm on an offbeat) in both right and left hand.

Once you've started understanding inversions and different rhythms, try and take an existing piece with a bass line that you're familiar with, and add notes in between when you'd normal prep your chord changes. This is called a walking bass line. Once you feel you've got the hang of that, see if you can take the existing bass line, and then created a walking bass line with inverted notes in the bass.

Feel free to pm if if you'd like. If you're interested, you can also check out some of my playing/style on Youtube to see if you can glean anything:

I Stand All Amazed/ I Pray in Faith mashup
https://www.youtube.com/watch?v=mF2hOfMS_Fw

Dreams to Dream arrangement
https://www.youtube.com/watch?v=b2EW6jxAEu4