I would like to find out if somebody is connected to my phone other than myself

Camobaby65 Said:

"I would like to know if someone else is connected to my phone or can be connected to my phone without me knowing it"

-------

Troubleshooting a Shared Device:

Four Things Here:

A. Modify your Credentials:

Having so much suspicion, consider modifying your credentials, ASAP, starting with a new password.

• Modify: your login credentials (using both a New eMail and a New Password) for Apple and each and all sites
• Associate: a different method of payment to your account
• Enable: Two-Factor Authentication for Apple ID PayPal and for all other accounts that have such an applicable option

B. Verify Your Devices:

Verify that your the devices logged in to your account or officially yours, by using this link: Check your Apple ID Device List to See where you're Signed in - Apple Support

C. Report this to Apple:

Have any suspicious items on the screen (i.e. messages)? Use my User Tip: Using the Photos App to Report Scams: - User Tips

and...

D. Set this Up Anew:

If you are so concerned, then reset your iPhone, as if you were to sell it. Perform as interacted here, including the backup: What to do Before you Sell, Give Away, or Trade in your iPhone, iPad, or iPod touch - Apple Support

That's not possible.