I’m all for upskilling myself. Is there a specific reason you picked SoapUI apart from it being mentioned a lot?
As amillionbugs said, Postman is a much simpler tool to pick from scratch. I’ve used both tools now, originally SoapUI and SoapUI Pro then when I changed jobs I moved to Postman because I found it a better fit for Rest Services dealing with json data.
Both tools have communities behind them to give you support too.