Hi!
First of all, welcome! The more, the merrier in terms of RP.
There’s a few things I would recommend. One of them is to get at least a vague idea of who your character is. This isn’t necessarily a thoroughly involved treatise on everything that makes Tiryen Tiryen. But even some basic points, like broad strokes of her personality, beliefs, things like that. If you get a general idea about that, it can be easier to expand on it later.
A lot of people use different add-ons to enhance their RP experience. The most common one is called Total Roleplay 3, or TRP3 for short. There are people who will invariably respond to this who can give you much better information about that than I can.
I would also recommend taking realm and realm population into account. This character is on Moon Guard, which is a pretty popular role-play realm. Wyrmrest Accord is also popular, too. From the word on the street, though, Moon Guard’s Horde population is a little light. You may want to make an alt to sneak around and get a feel for what’s what.
There are a couple of different kinds of RP. One of them involves storylines, and things like that? These are usually facilitated with guilds. If there’s a heavy sin’dorei or kal’dorei influenced guild, they do a lot of blood and night elf stuff. But there are also guilds that do a bunch of different things. Merchant guilds, mage guilds, guard guilds…there’s a lot. A lot of guilds have recruitments (at least, on Moon Guard) where they talk about what they’re about. Again, probably worth making a low level character and poking your nose around for that.
The other common kind of RP is referred to as “walk-up RP”. If you’re feeling pretentious, you can refer to it as ad hoc improvisational interlocution. It’s what it sounds like. This is one of the ways one of the above add-ons can help with that. You can have tags that indicate things like “Up for walk-up RP”, or they could describe things that could act as story hooks: “Tiryen seems uneasy, her hands never straying far from her weapon”.
Here’s an example of walk-up RP. Let’s say you’re…oh, the Love Is In The Air event, dealing with Crown Chemical Company in Silverpine.
Vanaelia: [Thalassian] Bal’a dash, sister. It’s good to see someone with some sense stopping these undead…things.
Tiryen: [Your response here]
And we go from there.
Probably the most important thing I’ll strongly recommend you take away from this is the fact that every person you encounter while RPing is a real human person. Treat them with basic respect. If you think they’re roleplaying something “incorrectly”, you can let that go. And remember to forgive yourself from time to time, too. You’re going to learn as you go along. Remember how you played when you first started versus now? Don’t be hard on yourself. And if you don’t like something, that’s okay, too. You’re not beholden to anything.
Someone had a slightly similar question in another thread, and I think the answer might help you a bit.
Good luck!