"Mother, I am starting!"
Swahili speakers often leave off "ni" when the meaning is clear. I believe this is only for first person
Yes, this is for first person singular only in present tence. There is however a gnomic tense with the same first person singular form as the shortened present tence.
It's a verb form that's used for "timeless" or "tenseless" situations, such as things that are always true or eternal.