new to RE ... how to best use cash?

[Tim Lee]

Hello BiggerPocketers.

I am new to this RE and am very excited to be in a community with so many experts.  This is probably a basic question, but I feel as though no question is too dumb to ask.

If we have recently sold a piece of property, should we take that money and pay off our other primary residence mortgage in full?  or, should we take that money and use it to venture and buy another property and leave the primary mortgage untouched?

for our example here, let's use the following figures:

sold a piece of property for $400k.

Should we take that money and pay off our primary mortgage to be debt free (not including property taxes, etc)?

or should we take that money, find two pieces of rental properties at $400k each and put a 50% down on both so that we can rent them out assuming all figures work out and we are getting some passive income?

or just take the money and pay off a 400k rental property in full?

I am learning drastically from this forum and hope you would pls share your knowledge with us so that we can pay it forward with others in the future.

thanks!