I am new to crypto currency and I don't know the Bitcoin is legal or not plse help me
Better if you just mention here of which country you are belong then we could all help you easily to find out if Bitcoin is legal or illegal in your place because every country has different regulations regarding the legality of Bitcoins. Most of the countries are declared Bitcoin is legal to use which is you can find out here
https://en.wikipedia.org/wiki/Legality_of_bitcoin_by_country_or_territory