Deleted two suspect apps but data was still in iCloud. Do I always have to delete data from iCloud after deleting the app?

I downloaded more than ten invoicing apps from the App Store yesterday to check them out for ease of use. I ended with five on my iPad to consider and entered trial info on each. This morning I noticed I had duplicate headers in my calendar for major holidays. I tried to delete one, but I could not. Then two emails were sent in my name but with a strangely long and oddly foreign email address, which were invitations to come to Easter at my house. I share my iPad with my husband and they were sent to his email account. in my name. I do not know if it went out to all my contacts!! Yikes!! I deleted all the invoicing apps, but found that it did not delete info in iCloud for two of them, which I then deleted. Why were they still in iCloud after I deleted the apps? How do I make sure the virus/malware is gone from my iPad? Is my calendar infected? I thought all apps in App Store were vetted and safe! I am worried because I want to set up my new home business electronically!