To subscribe to a community when you’re on its page, look near the top of the page, and you’ll see a box inside of which is the word “sidebar.” Click on that, and you’ll see a list of options, including “subscribe.” Sort of the same thing as you’d do in Reddit. To see only subscribed communities, look on the main landing page when you open lemmy. There’s three lines of boxes (will they look like boxes to me) near the top of the second line at the right there are three options: subscribed/local/all. It defaults to local, so just click on subscribed. Hope this helps. I’d include a screenshot, but I’m not sure how to do it yet. Maybe someone else can if you’re still not clear.