I get a lot of questions about workflows and SharePoint Designer. You will see that I did a series of blog posts on that topic:
You’ve read the blog posts now see the video:
Hopefully, all these will show you how easy it is to get into workflows for SharePoint Online.
As with most areas with technology, the rabbit hole goes as deep as you want it. SharePoint Designer is a very, very powerful tool that can create some really amazing things when it comes to workflows and SharePoint site design. Best of all SharePoint Designer is free.
So if you have been meaning to get your feet wet with automation in SharePoint Online, hopefully all this material will get you off the blocks to a flying start.