First find out if you’re left or right eye dominant as there’s no point in bringing the dart to your right eye if your left eye dominant as it won’t end well.
Have a strong base when throwing, don’t lean too far forward and keep your elbow up or a lot of your darts will end up going low,
should be a straight line going down from your shoulder to your foot.
Hold the dart how it feels most comfortable as there is no right way
When starting off I would say grouping the darts is the most important thing rather than just trying to hit the triple 20 every dart as you could end up scatting them all over the board, so say if your first dart hits the 18 try and hit the 18 with the next two darts then move on to round the world hitting the single numbers 1-20
Could be worth filming yourself and watching it back and also could be worth tweeting it to Wayne Mardle to see what he says, I’ve seen him give tips to people.