No text or data showing in my cells....

Excel accepts navigation but is not displaying what you enter, so first determine whether the values exist but are hidden. Type a value, select that cell, and check the formula bar. If the value appears there, select the range and choose Home > Clear > Clear Formats, then set Font Color to Automatic and Number Format to General. Also check that row height and column width are not zero. If the formula bar is blank too, create a blank workbook and test there. A workbook-only failure points to sheet protection, formatting, or corruption; an all-workbook failure points to Excel itself. On Windows, press Windows+R, run excel /safe, and test again. If Safe Mode works, disable Excel and COM add-ins one at a time. If it still fails, update Microsoft 365 and run an Online Repair. Before repairing, save a copy of the affected workbook so formatting changes can be reversed.