Weirdly, the only time I felt nerves in my first comp was in skewb finals, as I had out performed myself in R1, so I had given my self alot of pressure to beat that.
So, the only advice I can give is that you shouldn't try too hard to get very good results in the early rounds. Im not saying you should purposefully get worse results, but I am saying that setting a high bar in R1 of an event can make it harder to enjoy consecutive rounds of events, so you shouldn't go all out in the early rounds/events.
It also helps you from getting worn out easily and quickly.
Someone let me know if they have experienced this before btw.