I have stolen my iPhone 13 pro max which I have bought in May. Is it possible to find my phone?

See this support article→If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support, also contact your carrier and ask them to disable the SIM and blacklist the phone.

Also, Beware of a common phishing scam: You may get a text or email from “Apple” or “Apple Security” (or sometimes “Police”) saying your phone has been found and to click on a link to see its location. This is NEVER from Apple or from law enforcement; it is from the thief or fence to steal your Apple ID and identity. Delete any such message without responding to it. Apple never gets involved in lost or stolen devices→Avoid phishing emails, fake ‘virus‘ alerts, phony support calls, and other scams

If your phone was stolen resign yourself to the fact that you won’t get it back. See what insurance coverage you have, either through your carrier, iCloud+ with theft and loss, the credit card you used to buy it, or your homeowners/renters insurance.

Even if you can find where it is, that won’t help. If it’s local it is not wise to confront the thief; people have been murdered doing that. But most likely, when you track it with Find My, if it is powered on and connected to data, you will discover that it is in Srilanka, Kenya, or some other country that doesn’t honor the US phone blacklist.

If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support

If you enabled the "Find My" option on the phone, and the phone is powered on and connected to the Internet, then there is a good chance that the phone's location will appear on a map. However, if the phone is not powered on, or it is not connected to the Internet, then the current location cannot appear on the phone. The best that you can hope for in that case is a "last known location", which may or may not appear.

Be very careful if you receive a text or email that your phone has been "found". These are almost always scams that are trying to trick you into revealing your personal info so the thief can unlock the phone.