None and One.
Unlike the period at the end of a sentence (which have one or two spaces), the period following an abbreviation only needs one space. This is the general rule for abbreviations such as Dr., Jr., or Sr.
Two times
50 million gazillion
Mr. and Mrs. take a period, but Miss does not at it is not an abbreviation.
2
2
no spaces
1
In standard prose typing, you space twice after a period.
Just one space is fine, as you can start a new thought from that point.
You put the right quote immediately after the period and then 1 space.
One space follows a period after an initial.