You have multiple questions here:

- The Finder Folders view by date can be set in Arrange menu tab.

![folders][1]

To show those folders in the Finder side bar (create those Folders) then just drag them to the side bar in the location of your choice. To adjust size in the side bar go to system preferences General settings and change it there.

![side bar][2]


- To get the size slider go in to View tab in Finder and select show Status Bar.


  [1]: https://i.sstatic.net/RbE3J.png
  [2]: https://i.sstatic.net/0cSlQ.png