Help! Forming LLC taxed as S-Corp

[Alex M.]

In need of some expertise here.  Thanks in advance.

I have 6 rental units in NYC that I airbnb. 

Im also looking to buy a house for airbnb, likely in Tennessee or Georgia with an investing partner.

Question:

1) Should I form 2 separate LLC's?

2) I think I want to be an LLC taxed as an S-Corp to benefit from lower self-employment tax. Do I need to file this before 12/31/2017 to get it in effect for next tax year? Is this even possible this late in the year?

3) I am also looking to get Florida residency for tax purposes. Does this have any effect on where my LLC should be incorporated?

thanks in advance.

Noah