Is there a way I can AutoSum different rows together with the new columns I add everyday on Google Sheet?

I saw this Question and kept on wondering how do I apply this if I wanted to add different cells in a row. For reference, I am creating a lot of tables per day, each has 3 categories, namely: Cost, Clicks, Signup. I want to be able to create a formula where even though I add new table to the right, data will be automatically added to my Total Sum without manually adding it.

Apologies if my question is too difficult to understand. But here's a Practice Google Sheet for your reference.

Thanks!

I tried using the given formula from the cited previous question above, but there's no clear explanation with how should I apply this if there was only selected cells in a row and not actually getting the sum of the entire row. Help pleaseeee. Thanks a lot!

You may try QUERY() function.

=TRANSPOSE(QUERY(TRANSPOSE(D4:5),"select Col1, sum(Col2) 
where Col1 is not null 
Group by Col1 
label sum(Col2) ''"))

Or individual formula for each category-

=SUM(FILTER(D5:5,D4:4="Cost"))
=SUM(FILTER(D5:5,D4:4="Clicks"))
=SUM(FILTER(D5:5,D4:4="SignUp"))