Unless otherwise specified, all magi are wandering around the covenant, poking their noses into places, or settling into temporary quarters.
Dinner is about to be served, as the sun is going down (The stew and conversation took place in the afternoon, and because it is spring, the days are getting longer, but the sun still goes down early.
After dinner will be a council meeting, presumably to answer questions and officially welcome you to Lough Caillte.
Ever read a book? </rhetorical question> Works just like the characters there. Go back to pages 1-2 on the story thread and see how the first post by any character went.
Your character arrives. Describe his appearance, his reactions. Include "interior" stuff (what he's feeling, thinking) only if you want- that's optional. End the post implying what his intentions are, where he's going in general and what he intends to do, and let the GM reply as to the result of those actions. Repeat.
He probably has questions on their arrival - maybe they seek out the Praeco's, maybe they wander over to whoever is nearby. Maybe it's light, maybe later near dusk. Whatever you think adds to the story.
Don't make any huge assumptions for NPC's without SG authorization- maybe the guards let you thru the front gate (safe bet, considering), but let Dierdre or Angus speak for themselves. HOWEVER, you can post something like "Assuming he catches up to the other magi, he then..."
If you're not sure, then post less rather than more- walk up to the front gate, and shout "hello", and see what happens. The key is to not run ahead of anything random that might happen, but not get bogged down in detail of every insignificant step along the way. Include things that show your character, that are fun for others to read, and that others would naturally notice (like Daggin's webbed fingers, that he sort of hides as a habit, but doesn't worry about with other magi), but you don't have to reveal "secrets" that are only between you and the SG (for now.)
Get started, don't be shy, you'll catch on soon enough.
Play by Post is similar to group story writing, but differs in the fact that you don't control the actions of most of the characters.
Perhaps, then, this should help.
I've said everyone's arrived at the covenant. When "In the Beginning" ends, there will be the arrival of the 'traders' Diedre mentioned earlier. You can easily arrive with them and some other guests for the evening.
The scenery is wooded, and quite lovely. The locale is pleasant, and everything here, for the most part, is harmonious. Mention how Sheridan would react to being in such an idyllic scene. There are a number of sprites and brownies about, who would glady tell him where the covenant was, if he wished to arrive on his own. Make up names, even. Use my makeshift map in the handouts thread to give you some direction.
And to help you know when someone has posted, check the box "Notify Me when a reply is posted" before you submit it.