I'm about to make my first cut with/ in the MFT and don't want to mess it up!

Don't worry - it's only a piece of MDF.
I messed mine up plenty.
Not only with the depth of cut (I even cut right through once when I forgot to set the stop)
But also from not quite getting the blade square again after doing mitre cuts.
Ended up with a "Grand Canyon" ... about 5mm wide and quite deep.
Then ... after I'd made all these mistakes ... I just flipped the top over for a brand new fresh start.
Now I have a pristine top with a very neat cut that goes about 2mm into the table.

The local Festool guru here also messed up his table.
He then routed out a groove and inserted a new piece of MDF to restore it to its former beauty.