(I wrote this a few days ago but my internet broke, so here you go, a little late but I hope it helps anyway)
As ravand said, get the launcher. It will make things easier for you!
As for the ranks on the server, it is very easy once you get used to it. We have Builder, Grandbuilder, Architect, Grand-Architect and Master-Archtitect (which no one seems to have yet lol)
In order to get builder you can make a small plot (C- plot) /warp c- to get there which is 15x15 blocks big. This is a very easy rank to achieve. You just have to show us that you are putting in effort, using a few metas and starting to understand what the servers type of building is about.
Grandbuilder is pretty much the same but obviously more advanced. You also have to make a C plot (/warp c to get there) which is 46x46 blocks big for this rank.
Architect isn't all that easy to get. You have to think about style, atmosphere, detail and realism etc. This is also achieved on a C plot.
Grand-Architect is the highest rank at the moment and you have to make a C+ plot for that which is 151x151 blocks big. Obviously this is more advanced.
You can go straight from default to grandbuilder or even arch, so yes, you can skip ranks. If you have more questions just ask them here on the forums, or the server for instant replies. There is a lot to go thru but i think i covered the basics about the ranks.