Hi xrs12343, welcome!
The Wednesday shop rides are generally "hard" paced, as determined by the experienced riders who lead the ride. Distances is usually around 30-35 miles depending on wind direction. The rides can happen a couple ways: there is 1) some sort of structured workout (a couple minutes on, a couple minutes off), 2) a series of sprints and recovery periods, or 3) a hammerfest. The first two are better for newer riders, the last one is hold-on-for-your-life.
If you are newer and want to see how much better you can get, or if you just want to meet some other riders in town, you're welcome to show up. You can always either drop of the back and head home if you can't keep up, it's not a big deal.
Alternatively, you can show up to the night ride at 9 PM tonight, which won't be super hard and you might meet more people (I'm assuming you don't know a lot of people).
Hope this helps. If you want to head out for a ride with people anytime, feel free to post here and say so and you could get some other people showing up. Ask more if you have more questions.