Someone help?

I am creating a budgeting tool for me to track my actual monthly expenditures and compare them to my monthly goals. I have my goals set and some pretty good formatting for that, however, i decided i wanted to put in a sheet where i can log my transactions daily in given headings.

the objective is that i can click on a cell
picture 1.PNG
and add an expense, and it would just automatically add to the value in there previously.

Doing this would allow me to reference the expenses i record on a later sheet, where it shows me the remaining funds to my goal, my goal itself, etc.
Picture 2.PNG

The problem im having is that i cannot find the proper help / code with my specific problem. i cant seem to code the cell for a simple running total within that cell, where i dont have access to a formula, but rather just type a number and it adds to the prior number.
In addition, i would like to be able to add the macro to the other expense cells...

Lastly, can i add a ClearContents macro to a button to clear just the values, or would it also delete the macro here? if it would delete the macro and not just the values ive recorded over a month, what else would i use?

If i have made any sense to someone, please advise!!

Antonio Sibbio