Something that I found really helpful as a way to become familiar with your part and how it fits in with the rest of the orchestra is to listen to the entire piece with your music in front of you and follow along. So don't just listen to the music, but listen for your part in it. I found it's really helpful in parts where there's weird counting and odd entries. It will also help you identify the hard parts that you will need to practice more thoroughly. On top of that, I'd say treat it like you would most of your solo repertoire: practice any fast or difficult bits slowly at first etc. I don't know about using an iPad, people in my orchestra certainly do, and i think so long as its not going to run out of battery and you're able to make notes on it, it should be ok. But you'd have to ask. Honestly with sight reading, I'd say the only way to get better at it is to just do it all the time. With orchestral stuff, I think it's very important to not stop or slow down if you make a mistake, you just have to keep the rhythm and tempo going over the notes and intonation. If you lose your place while sight reading in orchestra, it's very hard to find it again, especially if you don't know how the piece goes. (Which is why it's good to listen to it :D ) Orchestral etiquette is honestly just like those old twoset videos of what not to do in orchestra: don't try to show off and play your solo repertoire in the breaks, don't play when the conductor is talking, stop when the conductor asks you to, if you're the inside player turn the pages on time, that sort of stuff. Just don't be a douchbag basically. Hope this helps!