Question

Translate the phrase by finding the infinitive and conjugating it to match the subject.

Answer 1

The verb to arrive is llegar. You since "I" am doing the action, you want to drop the ar at the end of the word. Now you have "lleg". Now all that's left to do is add the correct ending.
For I which is yo, the correct ending is o. To make it I arrive, you want

Yo llego

Answer 2

The verb to arrive is llegar.  since "I" am doing the action, you want to drop the ar at the end of the word. Now you have "lleg". 

the answer is 

"Yo llege"