or first person point of view?
Look at the books you like. If they are mainly written in third person (he said, she said) versus first person (I said), write them in third. Either way, the camera eye view of the story should be from the main character's point of view.
Think of a camera riding on your main character's shoulder. The camera goes where he goes. It can't record his facial features or what other people think of him. It can't record what's behind him, unless he turns around. We only know what the main character thinks, experiences, sees, hears. No bouncing from head to head.
Switching viewpoints can be done, but is usually done chapter by chapter, or scene by scene, so as not to confuse the reader. And, of course, is more difficult to write and keep straight.
in my main character's viewpoint.
Try writing the story in first person. Doesn't mean you have to keep it that way, but it can help you focus. I have frequently take a story I've written and switched it from third person to first or vice versa.
Perhaps you are telling the story from the wrong person's viewpoint. If you keep wanting to be in the boy's head instead of the girl's, try writing the story with him as the narrator, not her.
Or if both are needed to tell the story, can you have them tell the story chapter by chapter, switching off between the characters?
or present tense?
Most books are written in past tense, but some are written in present tense, though it is probably harder to do and keep consistent.
Whichever way you go, keep your story as chronological as possible. Lots of flashbacks confuse readers.
collected April 09
"Meet the Narrator" by Jan Fields
"Characters and Point Of View" by Laura Backes
1st Person Viewpoint
"Today's the last day of school, the only day of school I look forward to. I grab my basketball and head to Mr. Glick's class." Stanford Wong Flunks Big Time by Lisa Yee
3rd Person Viewpoint
"If Gil Goodson was to have a chance, any chance at all, he would have to run faster than he was running right now." The Gollywhopper Games by Jody Feldman
3rd person - Criss Cross by Lynne Rae Perkins
1st person - Remembering Raquel by Vivian Vande Velde
1st & 3rd person - If a Tree Falls at Lunch Period by Gennifer Choldenko