VBA Code for Sum & SumIf

I have just taken up learning VBA.

I have a Region wise Sheet where Regions (North, South, East & West) are mentioned in Column A and regions can repeat n number of times in Column A & Column B has numerical figures against each Region entry in Column A -

I need a code to Autosum all the numbers in Column B irrespective of the region & secondly I also need to use Sumif function only to find out the total of 1 particular region.

So basically I need two different codes.

How can I write that code?