Nothing wrong with your serve,,your feet staying planted as along as possible is good,,nice 2nd serve-can use as 1st serve too.
if you want your left foot to hop into the court first,,,
1.) slide your back foot right next to your left foot with knees bent-this is called a semi step--australian tennis school teaches this.
2.) as your coming out of back scratch--your knees unflex-like jumping up diagonally to hit the ball
3.) Ball toss just slightly in front of the base line
As you jump to hit the ball you'll land on the left foot in the tennis court, for a lefty right foot lands first and reverse the semi-step.
thats the basic's,,it has also been called the "Windmill Serve",,the book I read said this movement is what gave Mister Roscoe Tanner his tremendous speed on his serves,,actually--he slid his left foot over the court-very low-(continous movement) and then as he hit the ball right foot hopped on to the court---into ready position in one motion-feet even-ready to go---.......weight moving forward towards the target is key or its another lost serve. You have to trust yourself on Mister tanners serve technique--like riding a bicycle for the first time-try it.....