To access diablo II I need a new account or I can log on my current battle.net?
Diablo II still uses the old Classic Battle.net. It is separate from your battle.net account that is used for WoW/SC2/D3/Hearthstone/Overwatch/HotS/SC:R/WC3:R.
Just load up D2, go to Battle.net, create a new account (unless you still have your old one and it is still active) and you are good to go. It only takes a moment to make a new account, and it is free.