Multiple Challenging Excel needs....

I have been asked to help with a bunch of Excel functions and programming. There are a few that are beyond my level. I didn't come up with these ideas, just trying to help the person who did, so the only details I have are what they gave me. Any ideas on the following needs would be great:

-Can we link times in cells to the time and date of the computer so that it will change color when it is past that time and date in the computer. For example if it was 10a.m. today then any times or dates before 10a.m. would have red cells and times after 10 am would be green.

- Also I have written a sort macro for some data on google drive and made a button that user can click to sort data. Unfortunately the 2 columns I wanted sorted have to be manually selected then I can click the button and sort the data. I want to be able to just click the sort button without selecting data. Is that possible to put in my macro? Whenever I click on my sort macro button without selecting the 2 columns it gives me an error code stating “cell reference out of range (line3).” I am not sure what I need to change in my line 3 of code.

- On a different spreadsheet I would like to keep one day ahead of today and have a macro that automatically deletes older days. For example today is Monday so I would have Saturday and Sunday above that with 4 or 5 rows of data below each day heading. I want a macro that deletes the Saturday heading and the rows below it but keeps Sunday through Friday.

-Is it possible two have two columns sort by date and then by time automatically without the use of macros?

-I am trying to create a rolling spreadsheet. For example every time a new month/row is added to the spreadsheet all the previous data will rotate down. Not only will it rotate down but once the month is below a certain row the value will be multiplied by a percentage. Is this possible to do?