There are free tools from top RPA providers like Uipath and Workfusion. Here are the links to download them. Note that these are “free” and not open source. Please review the licenses before you use it for your specific need.
Download Uipath tool (look for community edition)
Workfusion Express Free tool download
I have more links for free tools to get started here: Nandan Mullakara’s answer to Which is an open source RPA tool that’s widely used in the industry?
Here are some open source tools I could find. I have not explored them and not much is known about these tools. So you will have to explore and do your due diligence.
Note that Most of them would need more advanced developer capabilities and would be more tedious. Also, the feature set would be limited.
SikuliX: RaiMan’s SikuliX
TagUI: kelaberetiv/TagUI
A quick review about this tool: The Democratization of Robotic Process Automation — A First Look at TagUI
Taskt: saucepleez/taskt
Roro: arviedelgado/Roro
Robot Framework : http://robotframework.org/
I have seen people use Test Automation tools.
Selenium: Browser Automation
You can also just use common language like Python. This is a good place to start: