Hi Katie
I joined this forum I think within a day of you, and it's brilliant to see what you've done.
Great toe dipping...many people learning to play an instrument just play other peoples stuff, to improve their technique, so a huge 'hat's off' to you for trying something, this will certainly show you what's involved, and maybe fire you up to do more.
Don't worry too much about how it sounds, it's yours, no one elses be proud of that.
That's why you're here, to pick up tips.
Keep going, do more, learn a chord or two, as one of the other postees mentioned, there is a lot you can do with just 1 chord, play around with tunes see what fits, think of the tune like a line graph, up and down, move it about a bit, make it interesting.
hope this helps.
cpm