Tax Year Prior to 2020: Where do i enter the purchase of a 2nd home?

It goes in the same area as your primary residence. Make sure to select that it's a Second home when you are asked about the loan.

Where do I enter my 1098 mortgage interest statement?

https://ttlc.intuit.com/replies/4793767

Here's an alternate method to get there:

• Federal Taxes tab (Personal in the Home and Business Version
• Deductions and Credits
• Your Home
• Mortgage Interest and Refinancing (select Add a Lender if you have already entered one)

You can deduct any interest, property taxes, and most mortgage insurance premiums that are reported on the Form 1098 Mortgage Interest statement.  You can also deduct any interest or property taxes from the settlement statement that are not already reported on the Form 1098 and not "pre-paid" and held in escrow.  

Additionally, you can deduct qualified points paid on a mortgage and qualified mortgage insurance premiums. (Points can also be called loan origination fees, maximum loan charges, discount points, or loan discount.)