I created my own instance by following the instructions in the video, "Oracle E-Business Suite Installation - INST". That installation uses a single Linux OS user, "Oracle". It appears that I cannot use AutoPatch to apply patches because it requires sourcing the environment with the "applmgr" user, which must have been setup prior to installation, and running "adpatch" from this user. "applmgr" user would be used for Applications and "oracle" user would be used for the Database. Should I have created these users instead of the single "Oracle" user shown in the video in order to apply patches? Do I need to re-install Oracle EBS? or is there another way I can apply patches using the existing "Oracle" user?

You can apply patches as Oracle user. The username owning the Oracle installation could be any. One user owns the full installation under a single node installation.

Thanks for the feedback. I'll research more on the patching process and give it another try.