If you need to stop a process from continuing onward, you can do so by halting that process. To halt a process, click on the process in your dashboard, and then click the button with three dots on it next to the Go to next step button. It looks like this:
You should see a popup with the option to Halt this process. Just click on it and the process is halted. Halting a process is reversible. Deleting is not.
To Resume a halted process, simply click the three dots again on a process that has been halted, and you'll see the option to resume.
To delete a process (not reversible, so please don't use this option unless you're really sure) just click Delete.