How do I participate on Lemmy instances outside my own?
If it's already discovered (see the next section on that) you can go directly by URL in this format. https://yourlemmy.server/c/coolcommunity@coolserver.com or by searching for coolcommunity in the search bar. You will stay logged in with your home server this way but can vote, comment, post using your current identity on that other server meaning you don't need a separate account. Neat right?
Discovering: Hey I can't see [x] newly started community on my server! I can't find [y] popular community from my small server! What gives? (IMPORTANT)
Some communities might not appear from All, until any logged in user of that server searches for it in the lemmy-ui (web) searchbar.
For example, to "discover" coolcommunity @coolserver.com from instance yourlemmy.server, you would type "!coolcommunity@coolserver.com" within yourlemmy.server's search bar and wait 10 seconds. Ensure that community has at least one post that can sync, and even then it may take a while to actually appear in some cases. If you set the filter to "communities", enter the community in that format and press search and nothing happens, that means it is discovered. If it says No results, try again after 10 seconds, check that you have spelled and formatted correctly.
That causes your server to "discover" it and will start syncing posts and be searchable and also available on apps like Jerboa. Only after it is discovered can you use a URL link to it in this format: https://yourlemmy.server/c/coolcommunity@coolserver.com I coined the term discovering here but in essence it's initiating federation and post-fetching from that community.
I signed up but nothing happened/Some notification came up but I missed it. What do I do next?
This server has a manual approval process. Usually requests are approved within 30 minutes but it can take up to 12 hours to get approved. Try logging in after an hour, if it works you are successfully registered. You won't get any notification at all of your approval unless you inquire about your application through outside channels like the monero matrix rooms.
How do I find more communities?
The communities page or searching for communities.
Help! Why can't I see any/many posts and comments on an active thread?
Check your Language settings. Select English, Undetermined and your native language(s) using Ctrl+Click in the webui.
Where are the "Hot" and Important posts on Lemmy?
Whichever server you decide with, you can use the All page from the home of your server, sort by Hot, New, Active. Just keep in mind again, if your server has few "discovered" communities you won't see much outside your own server. Subscribe to major, active communities that you might be interested in then you can look in your "Subscribed" page as your feed for buzzing posts.
Statspage on number of Lemmy users etc.?
Sure! FediDB, this page is also useful to find new servers to join.
Anything else I need to know?
Please be careful with what you share on the internet. This should be common sense as even content on Reddit can be archived before deletion.
This post is based on this Lemmy FAQ.
It would greatly help if you would actually describe your project instead of having people search for your account on a different site.