I am new to bitcoin, i want to know which wallet is the best and why is it the best.
If you are new shide2020 I'd have a look at the sticky on wallets for starters
https://bitcointalk.org/index.php?topic=1631151.0.
There are number of different types, that thread is a great place to start to give you some background on each type. When you know which type you want, then you can start narrowing down which wallet would be best for you.
Personally I went with Electrum for Android for my software hot wallet, and a Ledger Nano S for my long term HODL cold storage wallet.