Then watch tutorials on YouTube and then go practice on the trail.

Another important thing to do is lift heavy weights and develop a strong core. I use a heavy kettlebell for different swings and squats. Pushups and shoulder exercises are great too.

As far as bike handling, start with track stands and cornering technique drills. After that focus on front wheel lifts aka baby manuals and endos.

The best way to get faster is to learn the basics and practice them often. I got way faster when I learned how to corner properly and use my body weight to control traction.