If you're totally new to Rule Machine, the UI can be a bit awkward. To figure out how to get the IFs, I see you've already done so, but maybe watching the videos would help:
- How to Use Rule Machine Vol. 1: Simple Conditional Rules (not quite what you want--you need a "regular"/full conditional, not a Simple Conditional, but it's in a similar spot in the UI)
- Rule Machine 2: Advance [sic.] Conditional Rules (way more than what you want, as you only need a single condition and no combinations, but again, it shows you more of how the UI works)
The docs are also good. I know they sound boring, but they're full of good examples. 
Here is my preferred location for those (though you can also find this in the docs site): [Released] Rule 4.0
Finally, to give you even more ideas, locks generally only report a "locked" or "unlocked" state (some can do "unknown" and "unlocked with timeout" is apparently also an option that I'm not sure I've ever seen). Rule Machine also includes a few built-in variables you can use. Combining these facts, the following rule should work about the same:
Triggers:
Kitchen Door Lock *changed*
Actions:
Notify Pixel 3 XL: '%device% is %value'
Here, this relies on the fact that %device% is a string variable with the display name of the last triggering device (always going to be your lock here, since that's all there is) and %value% is a variable containing the value of the attribute ("lock," in this case, with likely values "locked" or "unlocked"--see "Current States" on the device page for what yours does) of the device that matched your trigger.
That being said, I'd just use the Notifications app for this myself.