Lookup between sheets, but set a variable?

I have two sheets. One is the primary. The other is the one where the data will be manually inputted. Both sheets have the same data, but the primary is the one everyone will read, whereas the second one is organized by "code" numerically in order for easier entry.

The primary sheet has the code too. How can I set the code in the primary sheet as a variable in the "value" in the "Lookup" function, then have the function look in my secondary sheet?

Let me know if I was bad at explaining my problem.

Thank you for your time!!