I guess they figured they didn't need one because the gameplay has basically stayed the same for over a decade (for guitar, the basic gameplay isn't really that different from GH1), and most people playing have played one of those games in that time. And the white notes are overdrive, and I believe the smaller notes are Hammer On/Pull Offs (meaning on higher difficulties, you can hit the buttons without strumming and have it register).
Hello friend and welcome to Rock Band!!
The white notes are Overdrive notes. You see the meter where your score multiplier is (Where it says X2, X3, X4, or blank)? You fill that up with those white notes (hit a phrase of them successfully without missing a note out over hitting) and when it's at least half full you can activate Overdrive! This doubles your multiplier! Overdrive is activated differently with different instruments:
Guitar/Bass: Tilt your guitar controller. Or you can press select on your guitar (YMMV I just discovered this from my Xbox One BIAB guitar)
Vocals: Say anything even the bottom of top of the chart is glowing gold. Or press select on your controller (recommended)
Drums: Complicated, since there are three different options to do it which you can fiddle with in the options. But the basics are they're gonna throw you a green phrase that if you hit the end note which is green, you'll activate Overdrive!
The smaller notes are Ho-Pos. If you're a beginner, don't worry about them. Just hit them like you do normal notes. Once you get comfortable with Rock Band and are looking to further your skill ceiling, then you can with about them! But they're harmless.
And best finger positions depends on person to person, but on the easier difficulties I would put my index finger on green, middle on red, ring on yellow, pinky on blue. On harder difficulties you'll have to shift around but you don't need to worry about that now!
I hope I helped a little bit and if there's anything you're confused about, I'd be happy to help more!!
I am guessing you're on the guitar, so it's quite simple.
The five colored squares that flies down the screen are your notes and to hit them you need to hold down the matching fret button and strum it at the right time. Hit the notes to increase your multiplier and by sustaining a high streak you'll get awarded with more points and stars.
I'll try and explain some of the features of the game:
* When you see notes that are smaller and have two white lines on the sides means that they are HO/PO (hammer on/pull off) notes which can be pressed without pressing the strum bar. They are frequent on fast parts and guitar solos and makes hitting them much easier. Mastering the HO/PO's is one of the last and trickiest things you'll do as a guitarist, so you're still far off reaching this part.
* Sometimes your notes will turn completely white, and by hitting all the white notes without missing you'll power up your guitar. You can see how much power you have by looking at the yellow line which is next to your multiplier score. When the yellow bar is halfway full you can tilt your guitar to go into overdrive which doubles your multiplier for a short period of time. Using the overdrive function on sections with many notes or tricky areas is smart if you need help passing certain areas. But using it on slow parts with few notes is a waste. Being smart and strategic with the overdrive function will net you a lot of bonus points.
* Sometimes you'll see notes with a long line, this means you need to hold down the button to sustain the note. You won't lose your multiplier if you release the button early, but you can get more points by holding it down or make cool sounds with the whammy bar.
* You can actually press the strum bar up and down to make it easier to sustain fast notes. It's very common for new players to completely ignore this feature, but doing so will end up in biting you. Learning up/down strumming is very importing to advance the difficulty tiers.
Just ask me if you have more questions about the game.
Woah thanks people. Better than any guide! Made things much more clear to me <3