Basically, all markup commands are in brackets and each one has a starting and ending bracketd comman. I'll demonstrate with spaces just inside the opening and closing bracket so it will display here, but realize the spaces won't/shouldn't be there in real live.
Here is the bold command. You can type it in, or you can click the little "B" button above where you type your post.
[ b ] Now is the time...[ /b ]
What do you mean Joy??
I saw you use the underline already!