I just upgrade to Quicken Deluxe and want to track a loan I gave a family member, and they are paying me back monthly with 5% interest. I am currently doing this with excel but would like to incorporate their payments + interest into Quicken
This link should walk you through the process. If you've made "prior period" entries already in Quicken you might want to temporarily change the computer's date back to the time the loan was made to get a full amortization schedule. If you already have a loan asset Account into which you've already made entries then probably the easiest thing to to is to simply use "today's" date and enter the loan's current value, remaining number of payments and so forth.
https://help.quicken.com/pages/viewpage.action?pageId=3217587
and…. how is the interest being calculated - did you offer a straight initial 5% - or is it a 5% on the current outstanding principal