I second this. I've done LPI Level One and it was quite hard. You need to have used Linux for a good while otherwise it's a bit of a trial by fire. I had 10 years of experience & still found parts of it hard as not stuff I used all the time. It is a little dated now as most of it is based round RH7.1 era.
I did a 7 day residential course with Firebrand training which was really good but expensive.
If you'd like to know more drop me a line