SeriousBrainDamage
Really Really Experienced
Using 1st person doesn't necessarily mean you have to use past tense.
You could very well combine 1st person with present tense.
(Though even with past tense, the storyteller doesn't have to know the course of the yet and if they do, they don't have to reveal it to the reader or could hold back parts of it.)
I wrote could.
I just offered a possible solution to this:
My problem is this. I want to write in the first person for the protagonist, but I'd also like to have some scenes where readers discover information that the protagonist isn't aware of yet, via third person scenes. I don't want to achieve this by having different viewpoint characters all using 1st person, because in first person there would be no way to generate mystery by hiding character's motives.