I know exactly what your talking about. This kid I was teaching to drive stick in his 240 did the same thing. Its because your thinking too much about shifting and your shifting at too low rpm/not giving it enough gas/not letting off the clutch quick enough. All of those combined will make you car jerk like that. Just go to a big space and learn to drive your car, dont worry about letting off the clutch too quick, once its in gear get the fuck off the clutch lol. And shift into 2nd after you get moving at a decent rpm, I mean you can take off from 2nd from a dead stop/low rpm if you really want, but youll need some more experience to do that. And yea like everyone else said, dont down shift into first. Remember brake pads are cheaper than transmissions...
**Since its your first stick shift car, and your still getting used to driving it, try doing shifts at around 3-3.5k rpm and work your way down as you get used to shifting/driving. Thats how I started and it worked for me till I got used to it,(and the kid I taught to drive lol) that way its not too high or low of an rpm and it will prob help you get over that jerking you get when going into second.**