Advice 4X
Sorry to post in the girls only sectin but the Advice 4X caught my eye, and after reading this is what NSWMTB is trying to do with its current series.
So, Dual Slalom is a good start, it has the start gate which you learn to handle fairly easy, no need to track stand at first the old DS rules said one foot on the ground at start which I still use. Two riders down a slope no burms just flat track around poles or cones.
You can start in DS and then start practicing 4X, first just roll the 4X track, just to get enough speed to get over the jumps but not to launch off them. You will have lower your seat as much as possible no sitting down in DS or 4X, the seat only gets in the way and if too high propels you over the bars. Move the body weight back behind the seat as much as possible on the up ramp of the jump back is always good, body weight forward of seat is bad.
First, off your bike and prefect the forward roll for when you fall, right handed and left handed, kneel down, and put your palm on the ground with fingers pointing to your knee. Move forward place elbow on ground, now shoulder, tuck head on to back, roll, judo style. Now when you fall you will hopefully not break the wrist or collar bone remember roll.
Once you can get around the track with out falling off, now the burms! Stop looking at the ground in front of the bike and start looking where you will exit the corner, eyes 1 to 2 seconds ahead, what is happening at your front wheel has already happened and you should start going around a burm faster and faster. Remember no jumping yet.
Next the favourite of the BMX the mono. Find a nice BMX rhythm section and start monoing. I have seen top riders try 3 to 4 different ways to take a section of the 4X track mono is a good method and almost as fast as jumping in most cases and does not hurt as much when you fall. If you can use the start gate, mono and ride the flat and burmed corners well you will be a very good rider, the next step is the one that injuries occur a lot, so think hard how bad you want this bit.
Jumping, start with bunny hop over a stick or rope, get used to moving the bike right and left in the air over the object, now a small ramp say 200 to 300 mm high and get used to landing on front wheel, back wheel and both wheels this time keep the bike straight. If you are really sure you want to jump the big ones, remember you will fall and it will hurt, collar bones break real easy, if you have access to a couple of old mattresses you can start jumping. First find a small jump fill the hole with mattresses and roll the jump. Once confident you can roll the jump you can start to jump the gap, once you have cleared the jump with the mattress start to move the mattresses out of the way slowly increasing the gap, keep the bike straight in the air if it is going wrong abandon ship do not stay with the bike they hurt you. I am well past my level of expertise here and will leave to the better jump coaches.