Long Terrm Capital Gain Tax Expemption - Question

Hello - 

I plan to sell my residential property next year (abt 2 Cr). In order to get exemption on long term capital gains, I plan to purchase another residential property. 
I plan to make the purchase this FY (March) and sell my current property next FY sometime Oct-Nov.

Can you please provide some guidance on my below queries?

1. I understand property can be purchased 1 year before or 2 years after the sale. Could you please confirm? Any specific ITR forms needed, as the purchase is prior to the sale?
2. As I will not receive my capital gains yet for the sale, can I purchase with my personal savings / pension amount (and not take any loan)? (I am Senior Citizen, 70 years)
3. Should the purchase be made with SALE AMOUNT or LTCG AMOUNT?

I am very thankful if someone can provide guidance here.

Thank you!