Hack? Fake phishing notification on iPhone?

I kept getting message from unknown emails which I know is definitely a scam. I’m very careful about answering calls from unknown numbers and responding to unknown numbers with weird messages, I don’t give out any of my information like that but recently I’ve been getting messages constantly from unknown emails with other unknown emails like a group chat with weird messages and as of yesterday I’ve been getting notifications saying my phone number is now being used for iMessage on a new Apple Watch, I’ll get them two times in a row after hitting ‘ok’ because there is no other way to get out of it I’ve checked my iCloud for any new devices or apple watches connected to my account and I have not gotten weird notification and careless allowed permission to access it. Is there a way I can stop this from happening? I’m tired of getting spammed by these unknown senders and getting those same notifications which is making me restless even though they don’t make sense. Is there another way to check that someone hacked into my Apple ID or is using my number for things? I also previously gotten messages from unknown emails asking if they could call me. They didn’t seem that weird I responded to one of them which might be why and a mistake on my behalf, it wasn’t after the second same message from a different unknown email sender that I realized it may have been a new way of getting information or numbers. Maybe that was how it started or where I went wrong. Is there a way to stop it? I haven’t had any money stolen from my bank account or anything, so are they just trying to get more of my information with a goal to steal my identity. I really think it is fake but I need something or a solution to stop all these to put my heart at ease.

[Edited by Moderator]