how do i log into my icloud accounts on my iphone
You can't really log in to the site on the phone. You need to do that on computer at iCloud.com. You can somewhat log in on the phone, but it's limited. You would need to long press the icon in the top right of Safari to switch to desktop view.
Press here:
If you just need to sign in to iCloud on the phone, do as stated above by Tartarus.