I plan to transfer as a 1st-semester freshman or as a sophomore could I be in programs such as co-op or pinnacle if I attend?
I mean 2nd-semester freshman or sophomore*
I think that the Pinnacle program is by invitation to entering freshmen only, but check with admissions to be sure. https://www.stevens.edu/admissions/undergraduate-admissions/special-programs/pinnacle-scholars
You should be able to join the coop program as long as you complete the prerequisites-
https://www.stevens.edu/directory/stevens-career-center/gaining-professional-experience/stevens-cooperative-education/co-op-undergrads
I would call admissions to confirm everything, regardless. Their programs are always evolving.