iCloud account acting strange, please help!

Hi everyone,

So recently (yesterday and today) my iCloud account has been acting strange on the two devices it's signed in on. Some strange things are the following:

•Requiring me to enter my password to update an app in the App Store (iPad)

•A popup message appeared on my iPhone saying that my iCloud account was signed into on my iPad for a new iMessage, but I had not used the iMessage app in a long time on my iPad. (iPhone)

•When I tried to sign into this website from my phone, it said that a device was signing into my account from Dallas, Texas, which I am nowhere near (I am in California currently). (iPhone)

Are these things normal? The first one might have been me messing around with some settings and forgetting about it later, but the other two? Are those normal? Has someone hacked my iCloud? I changed the password earlier today just to be sure. Should I be worried?

Additional info:

iPad model: Air 2

iPhone model: SE

OS: iOS 10.3.3, no jailbreak (same on both devices)