Different apps for Android, including antivirus, are covered in different reviews/articles, found here :
http://www.techsupportalert.com/mobile-apps/android
Please provide links to apps preferably on Google Play Store, because that's the safest place to get apps from.
1Tap Cleaner, CleanMaster, are good apps for cleaning, but cleaning is not so much required as in Windows.
Unless you have a rooted phone, start-up cannot be controlled.
Before posting more questions, please search the forum, and the articles to see if your answer lies there.