How to sort three columns of data at the same time, while making Column 1 weighted higher priority?

Here's one way to sort using your priorities.

Briefly described, the method is to reduce the sort values to a single value determined by the relative importance of the three values to be considered.

Here is your original table (with column labels reduced to initials to reduce typing here).

I've added two columns: Sort, containing the values determining the sort position of each line, and "initial order", added for my convenience to easily restore the original order of the rows in your table.

The formula below is entered in E2, and filled down column E to E14:

Click the header cell (E1) to select all cells (except the cell in the header row), then hover the pointer near the right end of the column reference tab. When the wide V appears, click and hold on it, then choose the Sort Descending menu item in the local menu to sort the table, based on the values in the Sort column.

Result when sorted:

Regards,

Barry

If you simply want to sort the columns, you can set up three sort rules. The top one goes first then the second sorts within those results and so on. If you later want to change the order, you can drag them around.

Sorting is different from categories. On iOS, you click on the circle with the three horizontal lines in it (menu bar at the top, 2nd icon from right) to make your sorting rules.