You can set up your favorite font as the default font so whenever you open a workbook, you have your favoriate font, please refer to the post How to Set the Default Excel Font for details.
At the same time, you can change the font in a worksheet anytime with the steps below:
Step 1: Select the cell or the data range you need to change font;
Step 2: Click the "Home" Tab from the Ribbon;
Step 3: Pick a new font from the drop down list, for example "Arial Black";
Step 4: You will find the different font now in the worksheet.