JWST’s current radial velocity away from Earth is just 468 mph, with 20900 miles to go. It loses a few dozen mph per day at this point; Earth’s gravitation pull is about one-millionth what it was when it was launched.
I do not know what the orbital insertion speed is. I assume the final burn adds speed to the current 468 mph.
Webb will do one revolution around L-2 every six months. Webb's distance from L-2 is roughly the same as the distance between Earth and Moon.
I recently read that docking and maintaining Webb precisely at L-2 would require significantly more fuel than the L-2 orbit does.
Also, being anchored at L-2 creates Earth and Moon shadow issues for Webb, which would impact the available energy, plus, cause fluctuating temperature issues with vital equipment.
What is Webb’s energy source if it’s hidden from the sun?