i started my riding interest with a big ladder drop. Sure it wasn't much of a jump, but it helped.
I jsut build a long 4 metre ladder, made very strongly (still using it for my now 2 metre drops) and slowly built it up. When I first started, I thought I was hardcore as, and put TWO WHOLE BRICKS underneath the end. Slowly over the days/weeks I built it up until it needed a downramp.
Kept on adding bricks....
It got to about 1 metre high on a 25 degree angle when I needed to build bigger and bricks just weren't cutting it on the strength front. I found an embankment that was about 3/4 of a metre high. Then started doing it all again, worked up slowly.
Honestly, the worst thing you can do is let mates push you into moving too fast or criticise you until you do something. If you crash, you never want to do that jump again if you weren't up for it. I did a 2 metre drop when I didn't want to, crashed (not because of my own fault, it was the lander) and I couldn't get the guts to do for weeks when I came back to do it 2 months later.
So honestly, take it at your own speed, get a feel for how things flow when you're in the air.
Finally, buy whatever you want to protect yourself (within reason...). When you are doing drops over 1.25m it might be worth buying a full face. If you can complete downhill courses quickly and you want to go faster, feel free to get body armour. One of the things people tell you when you say you're gonna get stuff is "You're not doing big enough stuff to need it". If you're miles off, you probably shouldn't, but if you're close, you might need that gear to push yourself the next level.
Personally, the best starter gear are Fox Launch Guards ($110AUD) and a pair of gloves (they don't even have to be proper riding gloves). Of course, wear a helmet.
BEST OF LUCK!