First of all, welcome to D&D!
That said, I think you are overthinking this way too much. As a new player, there is so much to learn and pick up, don't expect to soak it all in before your first session. If your fellow players are worth their salt, they will be nice to you and help you out until you get more familiar with everything. Don't be afraid to ask them questions! Especially your DM should see it as his duty to teach you.
As for your character, Rogue is a good, classic choice.
Don't worry about hybrids, multiclassing and all that - doing this has a cost that is better spent on other things.
Also, don't worry about making all the wrong choices - have a look at PHB 1 page 28, "Retraining". You can always switch out feats and powers later. So just pick feats and powers that look good - if you don't like them after all, just switch them out when you reach level 2.
Now, there is one thing that you should learn as a Rogue - Combat Advantage. Your best class feature, Sneak Attack (page 117), depends on it. Read the chapter "Combat advantage" on page 279. Don't worry if you don't understand it all yet, you'll get the hang of it after two or three sessions.
The easiest way to gain combat advantage against an enemy is flanking (page 285) - in short, making sure that the fighter or another party member is on the other side of the monster.
If you're a new player in my party, with a Rogue, and you already know how to flank and Sneak Attack, I'd welcome you with open arms.
But you know what the most important lesson is? Don't worry too much, relax and enjoy the game!!
That said, I think you are overthinking this way too much. As a new player, there is so much to learn and pick up, don't expect to soak it all in before your first session. If your fellow players are worth their salt, they will be nice to you and help you out until you get more familiar with everything. Don't be afraid to ask them questions! Especially your DM should see it as his duty to teach you.
As for your character, Rogue is a good, classic choice.
Don't worry about hybrids, multiclassing and all that - doing this has a cost that is better spent on other things.
Also, don't worry about making all the wrong choices - have a look at PHB 1 page 28, "Retraining". You can always switch out feats and powers later. So just pick feats and powers that look good - if you don't like them after all, just switch them out when you reach level 2.
Now, there is one thing that you should learn as a Rogue - Combat Advantage. Your best class feature, Sneak Attack (page 117), depends on it. Read the chapter "Combat advantage" on page 279. Don't worry if you don't understand it all yet, you'll get the hang of it after two or three sessions.
The easiest way to gain combat advantage against an enemy is flanking (page 285) - in short, making sure that the fighter or another party member is on the other side of the monster.
If you're a new player in my party, with a Rogue, and you already know how to flank and Sneak Attack, I'd welcome you with open arms.
But you know what the most important lesson is? Don't worry too much, relax and enjoy the game!!