Q: okay, I've got my staves and bars. now what?
A: put notes in the bars. let's start with a "quarter note." you can search online for what it looks like. we're not doing pitches right now, just rhythms. so it doesn't matter which line/space you put it on. just put 4 of them in the bar. a quarter note is 1 beat's worth. so if you put 4 quarter notes in each bar, that is basically like when we were counting beats before, except you are playing a note on every beat. if you search online you can probably find an image of exactly what 4 quarter notes in a bar looks like. if you can't figure out how to get your quarter notes looking right, i might be able to scrape together an image, but if you search for an image of 4 quarter notes you should see what this looks like. it is called quarter notes because it is 1 quarter of a bar. in another world, it might also be called a "single note" because it is one BEAT. that would be in a world where the notes where named based on beats. but they are not. in our world, (earth, etc) they are named according to how much of a bar they take up.  (assuming your music has 4 beats in a bar, which most music does.) quarter notes. worth 1 beat. 4 can fit in an ordinary bar. put 4 quarter notes in the first bar. now go download a metronome and i will tell you the next step