Canva is an online design tool for everything, either from the templates or from the scratch. You don't need to be a designer to have a professionally made cover, logo or a video.
It is not completely FREE, but even with the free plan you can make much with it. Canva is the best software for visual editing and you can easily spend hours tweaking your content.
Other visual editing tools can be frustrating and tedious to learn, for example the Adobe or Corel take time to learn how to handle, while Canva is simple and easy to manage. Once you get a hold of it, your tasks will be done in no time. It is user-friendly and rich in premade free templates.
From the options you can create content for the various social media profiles, upload PDF or create custom size content. It offers an option to connect your Twitter, Instagram, Google... etc, and share created items on those networks.
Some features are locked in a premium version - such as resizing images, downloading images with transparent background or compressed images.
If you want, you can try Canva Pro FREE for you and your team for 30 days without obligations. You can cancel any time and support will remind you 3 days before trial expiration.