I woke up to my email being bombed with spam. I looked it up and people said it's to hide when hackers have a made a purchase. That's when I came to an email from home depot stating I bought something. I got the order cancelled, but the thing is, I don't have any billing info saved on my account, so they ultimately used their own card, but my account. They also added new addresses to my profile. My question is why even go into my account and change my address only to just use their own card. Can anyone help?

They will order a new card on your account to be sent to there address.
Also they may have a way to hack to get your account number (you would be surprised)

So you need to go or call them, cancel that card, change all passport and sign in info, and change any address change, You need to report it to them as an ID theft and even report to the police in case of other fraud actifity

I deleted any new address that they put in. They used their own visa card to purchase an item not a home depot credit card. I checked and they didn't sign up for one. I also didn't have any billing info saved on the home depot sight just my email name and number. So did they just buy something on my home depot account to "test the waters" so to speak to see if I check my emails or something?

You can never be sure what a criminal is up to so check and change everything just in case this is not a test. I don't think they would waste their time with a test, so assume the worst, and take the very good advice of Fr. Chuck and report this breach and protect yourself properly.