First, your company logo should be in your sheet format, not your drawing template. Sheet formats and drawing templates can be confusing. I explained the difference between the two in my second post on this discussion: https://forum.solidworks.com/thread/57204. Assuming that you do have a sheet format saved with your company logo, then after adding a new sheet, you can RMB on the sheet tab at the bottom of the screen and choose Properties. That will take you to a dialog box where you can select the desired sheet format.
If this doesn't take care of it, feel free to ask more questions.