I failed my first time too. Dw .reflect and learn you can do it.
Complete the workbook for 10 points.
Master buffer overflow . Look over the one in course material.
Have some scan scripts.
Have a methodology. Practise it.
There are lists of Oscp like VMs on vulnhub. Smash them all.
Eat plenty good food. Sleep well. Excercise before if u can.
Pick a good time to start the exam. Plan for sleep.