playing

In what respect? 

can you resign, do you have to message person at end of game or at all...

The formalities of over the board chess go out the window somewhat online. In my experience it is rare that messages are exchanged of good luck at the start or good game at the end, but if someone does offer this it's of course polite to respond in kind. With resigning some folks get pi**y about people not resigning in a 'losing' position but really it's up to you. You should only resign when you yourself see that it's hopeless to continue. But I see you only joined a few days ago so I presume you are a beginner player? If so I recommend not to resign games because it's all good for learning even if you are just seeing how your opponent checkmates you. Also other beginner players you face can also make big mistakes which may allow you to draw or even win some games which look utterly hopeless. 

ok. thanks👍