Need help in removing certain things from my iphone

If you don't have access to the device Apple cannot help you remove individual items from it.

Read about Find My iPhone's erase feature iCloud: Erase your device

That is the only way to try to remove data from a device that is not in your hands (provided you enabled Find My iPhone). That removes everything provided the device can respond to the command from Apple's servers (either Wi-Fi or cellular). Bear in mind once erased you can no longer try to track it.

You can sign into your iCloud account and do a number of things using Find My iPhone IF you are signed into the device using your account and the FMiP service is turned on and the device is connected to the Internet.

You can not erase specific information such as individual contacts or photos from the device. You can erase the phone completely, lock it by placing it in lost mode, play a sound to help locate it if it's lost, track the location, etc.

Removing it from your account will remove the activation lock from the device and will also mean you can no longer perform any of the above actions.

If you have find my iphone enabled in your icloud settings on the device, you can login to your iCloud account (www.icloud.com) and execute a remote erase. DO NOT remove the device from your list of devices there in the find my device app - doing so will break the remote command connection, and disable activation lock so anyone with it can set it up and use it as their own.

Once the remote erase is executed, you will not be able to track it any longer, but as long as it is listed in your iCloud account, activation lock prevents anyone from activating and using it.

If you did not setup find my iphone on the device before it was lost or stolen, then there is nothing you can do remotely to or about it now.

No. Removing the device will not erase anything at all from the phone. I will remove the activation lock, which is the anti-theft mechanism built into iOS that is designed to render a stolen phone useless to anyone other than the owner.