Citing data can be tricky, but the way to figure it out is to adapt available guidance to your situation. In the case of this class, you'll want to adapt the IPUMS suggested citation (link below) to the Chicago author-date style. For example:

Minnesota Population Center. 2020. Integrated Public Use Microdata Series, International: Version 7.3 [dataset]. Minneapolis, MN: IPUMS. https://doi.org/10.18128/D020.V7.3

Note how the date is after the author, which, in this case, is an institutional author, the Minnesota Population Center.

Handwritten notes are great (but hard to back up), and copy-pasted links are fine, but if you want something a little more searchable, re-usable, and less easily lost, here are some options for saving and organizing your research documents. Plus, these tools help automate the formatting of your citations for your paper. These are especially useful for students writing (or thinking about writing) comps.

Remember: Zotero and Endnote save a lot of time and typing, but you still need to check citations for accuracy and correct format yourself and will need to make plenty of edits by hand. 

Zotero

EndNote