I neglected to mention (’cause I forgot about it) there is another rather simple method to get a watermark on your photos with Photoshop. If you are subscribed to the Adobe Creative Cloud there is within the All Apps listing, one called “Watermark 3”. It is free to download and gives you the opportunity to put in watermark text ( any font you choose) or a logo/graphic file. Pretty easy, it is a plugin for Photoshop and resides in the plugin panel. The watermark becomes a separate layer so you can alter its color, transparency, size, etc.
Give ti a try!