Howdy there, newbie! If you're reading this, that means you've discovered the forums. You are a rare breed.
The first step to becoming an elite is to read up on the game's wiki. You will want to pay particular attention to the four strategy guides for shields, swords, guns, and bombs. Read the entire wiki before proceeding to next step.
The second step is to read the forums, starting with this "New Recruits" section. If there is something you don't know that the wiki doesn't tell you, use the search bar! I can't tell you how many times newbies irritate the forum users by asking the same questions over and over again.
The third step is to practice and challenge yourself. You won't improve if you always do the easy stuff, or if you log on rarely. Do the danger missions, fight in the next tier as often and early as possible, and do all the rank missions. Carefully read the conversation missions, as they often have vital information or fun lore.
Finally, be a responsible player. Don't spend your crowns and energy on worthless items; plan ahead, and buy only what you need. When you type, write clearly and properly. Treat other players with respect; you never know when you will need to count on them. Be kind and generous, but be cautious, too; there are hackers and scammers, even in this game.
Now go have fun, and enjoy being an elite player of Spiral Knights!
Some people (like me) log on quite rarely, and it takes time to actually advance star levels. Here are some of my tips that are specific to going up lines:
A good line to start with would be the Brandish, as that introduces the different damage types. Nightblade will make RJP runs a lot easier, and you can get your shiny new Antigua faster :)
On the other hand, you may want to go up the calibur line. These swords deal ok damage to everything, and excels at crushing turrets. Sneak up behind them, release the charge, and KABOOIE!
Now for guns. A popular starting one would be the alchmers. These deal some statuses, or some raw heavy damage. After you get your antigua oand pulsar, go up those 2.
Bombs, i'd suggest the blast bomb,mist and shard lines. What type of shard would be personnel choice.
Armor and helmet...hard choice. Go up wolver. I went up chroma first, and it made RJP a joke when I was 3 star. However, wolver is an all around sort of thing, and the vog set will be quite useful later.
Shield is really just by preference. Ive seen plenty of different shields being used, and except for Omega Shell, all were pretty useful.