Is there a function similar to the Selenium IDE funciton "storeElementPresent"

What I would like to do is something like this “Is an element present. If so then save true into a variable”. Is there a function like this or would I have to do it through an if statement?

You can try with this:
https://docs.katalon.com/display/KD/%5BWebUI%5D+Verify+Element+Present
For example:

isButtonPresent = WebUI.verifyElementPresent(findTestObject(``'Page_CuraHomepage/btn_MakeAppointment'``), ``20``)