(WARNING! I'm not an expert but I'll try to explain the basics as well as I know. Feel free to correct me!)

As mentioned before, Second Life takes a lot of time and patience at first. Keep in mind that the platform was originally created in 2003 (!!!) so naturally it's not quite as user friendly as newer similar games. At the same time, it's by far the most advanced "metaverse" platform that still exist to day! It's a lovely chaos, mixing old and new and it's constantly evolving due to it's extremely committed userbase. The learning curve is big and it requires a lot of trial and error, but once you understand the basics, there's so much you can do with the platform!

Second life is free to join and download. That being said, you mostly won't get much out of it without spending at least a few €. There are premium membership options with a weekly allowance, or you can transfer money to your account from the Second Life homepage. The currency in SL is called Linden Dollars (Linden Lab is the company behind SL). The fun thing is that you can also transfer your L$'s back to USD, so if you make any money on the platform, you can change it into real money. If you're on a budget and still want to come and explore, there is also a lot of freebie stuff around. You are in total control how much or little you want to spend. 

Second Life has had a lot of changes since it's release, and one of the biggest changes between the original 2003 SL and the place we know today, is MESH! Mesh is the capability to bring 3D models, known as meshes, created in third-party tools into Second Life. (The Sims players might be familiar with mesh, it pretty much means that your clothes won't be just painted on to your avatar. Mesh is the 3D shape of the object). Mostly everyone uses a mesh body and head these days, and it's the key to making your avatar (aka "avi" in SL slang) look modern and pretty. This is where you should invest some money imo. Getting the perfect avatar for your taste is one of the biggest things that makes you enjoy the game. I could spend hours just editing my avi! It's like GSM but in 3D 

TO BE CONTINUED