Pretty easy lol jk
I guess it depends on your English reading/speaking/writing ability (duh!). Anyways, if your skills can match a native-speaker's, then it won't be unheard of to get a perfect score (120/120).
Most people would probably agree that the reading section is the most challenging part. While speaking was easier, and writing was easiest.
The only advice I can give is study the practice material from TOEFL, and do your best. That is the type of person I am. I try not to fret over tests, exams, etc. If you've done your best, what else can you do really?!