A
firerake will cut through grass/plants very well.
If you are going to build trails you should consider joining a trailcare crew.
You will work on all types of trails and repair problems, hopefully when you do this you will be taking a mental note of what may have caused these problems and also the solutions to these problems so that when you are working on something of your own you don't make the same mistakes.
If you do this you will save yourself alot of repairs in the future.
And as often stated on here you should not build where your not allowed to build.
Start with repairs to existing trails on trailcare days to get your techniques sorted, maybe by the time you are ready to build new trails you will no longer need to as the ones you already have might be riding great.
also keep all skill levels of riders in mind when creating/fixing trails, and don't make them dangerous.
An example of this might be to remove fallen branches/sharp sticks off the side of a trail where it is likley that someone might crash and fall. or to remove awkward rocks and logs under ladder bridges to allow an even surface for people to land on if they come off, hopefully saving someones ankles.