If you start a new character in ME:3, they start at level 1. I think. I've never used a new character, and always started from ME:1 in my two playthroughs of the game.

when you import from ME:2, whatever your level was at import is your level in ME:3. You know how 30 is the maximum in ME:2? Assuming you hit 30 there, you begin at 30 in ME:3. If you got to level 27, you start st 27 in ME:3.

I'm pretty sure that's how it works.