Nah, whip out the 89, not the 84. Has capabilities that are more useful for some stuff, especially in calc II and beyond like expanding polynomials in partial fraction decomposition, etc. Nothing wrong with using the calc as long as you understand how the operation is worked out, in what order, and why.
Edit: in seriousness, the 84 is fine for now but in my calc 2 class I’m currently taking the ti84 students have to do much more work on some problems than the ti89 students. The course technically requires the 89 but some students are hard-headed.