Hey, the sequencer is not very intuitive, but here are some tips: Always enter notes in multiples of 8. A standard bar in most electronic music will be 16 notes. There should be 64 available steps in the sequencer, so that means four lots of 16 notes.
I enter notes by counting them out, including the rests. Rests are a 'blank' step without a note, you enter them with the rest/tap tempo button. You need them to give your sequences some syncapation. (It might not be spelt like that)
Here are some examples, where 1= any note (preferably in the same key), and r = a rest.
1rr1rr1rrr1rr11r.
1rr1rr1rrr11rr1r.
11r11r1r1r11r11r.
11r1r1111r1r1rrr.
Hope that makes sense.