Can I hike alone?

I am 21 years old and want to visit Hawaii this year. :)

Unfortunately no one comes with me so I have to do the trip alone.

I want to hike the most frequent and beautiful places, but im alone.

i have never hiked or climbed mountains in my life, not even in my country.

Would like to see places like this on Oahu:

is it dangerous or feasible? are many people there? i could maybe ask others if i can walk with them.. unfortunately i am completely alone.