As a newbie to cryto you should try and understand the various types and forms of wallet. The cold, hot, ooftware and hardware wallet. Electrum is a software wallet, it stores your bitcoin in the software downloaded in your phone or device. This allows you to store your crypto over long period of time, and you make transactions. It doesn't send any data to the server, therefore even if its hacked, your coins remain safe.
It is secured, as it has a 2 factor authentication
About how large its community is, the number of people using electrum wallet, but from recent starts, it shows that more than 10% of transactions with bitcoin was done with Electrum wallet. If this is the wallet for, why not go to your play store and get going with your business with Electrum