Can I use an image that I find online?
If you create the image then you can! But what about using some else's image?
Ask yourself the following questions:
Are you using the image sparingly?
Are you not going to make money off of it?
Are you using it for a scholarly purpose?
Are you changing the meaning of image (parody)?
Are you getting consent from the owner?
If you answered yes then you may be able to use the image without copyright issues. If the image has a logo or slogan, or has someone famous then you may have additional legal concerns. Best practice is to get permission to use the image, especially on social media.
As always, speak to an attorney first before using an image for your business. Thanks!