People do not fail to attend events because they were unconvinced. They fail to attend because something practical was unclear.
The five facts, in the first two lines
Date, start time, how long it runs, exactly where, and what it costs. "Evening" is not a time and "central" is not a place. If it is free, say free — that is a filter people use.
Say who it is for
Beginners or experienced, adults or all ages, whether you need to bring anything, whether there is a limit on numbers. An event that tries to be for everybody reads as being for nobody in particular.
Post twice, and time the second one
Once when you have the date, and once two or three days before. The second is what converts: most people decide what they are doing this weekend during this week, not a month ago.
Give it a title somebody would search for
"Beginners' pottery evening" beats "Clay & Company presents: Session 4". The name of your series means something to you and nothing to the person deciding what to do on Thursday. Put the thing, the level and the place in the title.
Say what happens if plans change
Whether it runs in bad weather, whether tickets are refundable, what you will do if too few people come. Events are bought on a small amount of trust and this is where most of it is won or lost — and a cancellation handled badly is remembered far longer than the event would have been.
Count on the day, and use it next time
Note how many came against how many said they would. That ratio is the single most useful number you will have for the next one, and almost nobody writes it down.
Make arriving easy
Nearest transport, parking, which entrance, and what the place looks like from outside. A photograph of the doorway is worth more than a photograph of the room.
One listing, updated — not a new one each week
For anything recurring, edit and refresh the listing rather than reposting it. Reposts fragment whatever attention the first one earned, and repeated near-identical listings are the pattern moderators remove. A single listing that has been running for three months with current dates reads as an established thing, which is the impression you want.
List it in Events, or start a new listing. If you are teaching something regularly rather than once, Learning & Classes is the better home, and the tutoring guide covers it.