Hello i am new and i am really interesting to start Diablo 1 , but i would like to know how easy is to play online with other players ?

There is still a community online... But for how long? I don't know :)

Hi bro, welcome.
Go to this post if you want to play Multiplayer :)
https://www.gog.com/forum/diablo/hamachi_networks_network_naming_scheme

But I think maybe is better if we make a group, in Facebook,or WhatsApp, or somewhere, and when someone of us is online just need to say to everybody

Hey brolly, I like dat DBZ character.

Anyway, I have a new character also. I will play multiplayer with you on the battle.net. sound good?

+1 whatsapp

Jeje yeah I like brolly too jaja, I always use this name :p.
I know that is much better play online in batlle.net, the big problem is that there is a lot of bugs in batlle.net, the most famous bugs here are:
1. Impossible to play, error 6114.
2.- imposible to play in hell or any other difficult
3. Some image bugs
So, there are none of those bugs in Multiplayer Diablo HD playing through IPX, we are using Hamachi, i have seen that some guys cant see the games created, but i dont know how frecuently it will happens, but if i am not wrong, there is another network programs to use in case that you have problems with Hamachi.