I've been told my beats are off beat.
How exactly do you stay on beat and how do you use the metronome to help you? I've been searching heaps but there's no videos or any sites that explain it properly.
The question is anything but clear! But I'm guessing someone has told you you're emphasising beats 1 and 3, when they think it should be 2 and 4, or possibly vice versa. It's quite easy to get confused - does one clap on 1 and 3, or 2 and 4?
Well, it doesn't really matter. As long as one knows where beat 1 is, either will do!
In pop music, often beat 1 is signified by a thump on the bass drum. 1 is recognised in most styles of music as being the 'main' beat in the bar. The most emphasised. Often with a main word sung slightly louder in a lot of songs. Or listen to the count in - 1,2,1,2,3,4,1. Once that's established, the song rolls out in time. You could then clap/tap/nod on 1 and 3, or 2 and 4, as long as you count or feel where 1 is, the others will follow!
There are many q/a about this subject already here - take a look.
If this isn't anything helpful for what you are asking - let me know, and I'll delete it.
It can be hard to develop a consistent beat working only with a metronome, because one's own playing is often louder than the metronome, and because you can have a slightly inconsistent tempo and still not be obviously "off" from the metronome.
The best thing is to feel the beat, or the tempo, in your body. Find different ways of moving around the room while either listening to a recording or singing the music. Then when you sit down to play, set yourself up mentally before you start, by remembering how that felt.
You can also conduct the music, as a conductor would do, while you are listening or singing.
For some pieces of music, it can be helpful to be aware of the subdivisions as you are playing. Perhaps the passage has some quarter notes and some eighth notes. While you are playing the quarter notes, imagine the eighth notes marching along underneath, in your head.
If you do want to use a metronome, try listening to it with an earbud.
I developed my sense of the beat and rhythm as a small child when I did things like learn to dance and skip down the sidewalk and I listened to a lot of beat heavy music. Also I was fascinated by the person who led the choir at church and as a child often imitated the arm movements he made when I heard music playing, pretending to be the band leader myself. Then came piano lessons and the metronome. I guess my point is that I've been surrounded by rhythm my whole life, and I'd suggest that you might benefit yourself by finding stuff that is rhythmic in nature and try surrounding yourself with these things in hopes of some of it becoming part of your nature.