Ques. Is an antivirus necessary for android phone? If yes which one would you recommend? I would prefer a free one.
Ans. Antivirus is not that much needed as it is linux based operating system. But still if you want to, You can go with avast antivirus.
Virus infections in phones are a very rare occurrence, just avoid downloading apps from non trusted sources.
Always download apps from the official stores like the play store.