Don't panic too much - but you can hit problems.
As long as you arrive at the other end in one piece getting lost for a while doesn't really matter - even if you use 121.5 for a fix and track/distance nobody will mind - in fact, its a sign of blooody good airmanship.
During my QXC, I got Brize to vector me around all of the restricted areas, purple airspace and busy fields for a good 45 mins after I got a little "unsure of position"!!!!
The important thing is getting you slip signed at the two away landings. If you do something dangerous in the circuit or on the ground, they may not sign it and that, quite rightly, is a failure!!
If this year is anything to go by, you will probably make several attempts to get it done only too be let down by weather before departure or en route. So don't be anxious to get it all done now!!!
Thats my twopennyworth - hope it helps - the elation you feel when you've done it is the highest high in aviation after your first solo.