How to address, po?

[Deleted]

[In the name of the Father, and of the Son, and of the Holy Spirit. Amen.]

I am a little paranoid in how I write in some cases. I feel like I am the rude girl. I actually can't stop hyperventilating at times when things go wrong, it is some sort of panic attack I think.
In my country, the way in respecting people in a formal manner is saying "Po" and "Opo". While addressing adult people is either "Ate" or "Kuya" or "Miss" (I think Vincent is Mister).

I kinda need to know since the reason why is because I feel I was rude to people, even though I tried many times to write in a polite manner. My cultural teacher says that "The tone of the voice is what people focused even though you are trying to be nice to them." 

The problem is that...I really don't know how to address the other role-players. My true age is 17 and I have no idea how old the other role-players were, I think they are older than me or younger than me? I am not sure...
So how can I address you? Just your usernames or something else?

[Gypsyrose Fairy]

Hello there ,my name is Gypsyrose Fairy, and I am 26 years old. I love old fashioned movies and I am a big fan of anime. Puella Magi is my all time fav, next to Sword Art Online.
I am sorry if I caused you to get paranoid that was the last thing that I wanted to do. Also if you want to show people that you mean things in a nice way, always remember to say please and thank you, just a little tibbit, works in real life and in here. You have been nice and very sweet.
You are a very sweet girl as I keep on saying, I would love to plot with you someday.

It takes time. Heck the only person I plotted with for a while when I first started out was Rukia and Winxy, maybe a few others here and there. Then in time I grew a vast amount of friends,  very near and dear to my heart. It takes time. People are really nice online and pretty soon you will find your own rp family and feel right at home. I would love to get the chance to know you better too and maybe someday, who knows, we can become online sisters, if fates allow. I really do like you and I want to get a chance to know you better. And that's the truth.