Is c59 providing power to that entire circled area or is just two points in between it? What about the other row of caps above it?
Could someone help me understanding the markings of this schematic? What the little numbers I circled in red and yellow are
The numbers you have circled in yellow, are the BGA ball numbers on that IC (cut off on the right side of the schematic photo you included).
The numbers you have circled in red, are the page numbers in this schematic diagram where that "net" (circuit connection) continues. On yours, it looks like pages 23, 21, 12 & 4 all have components connected to the PP1V2_SDRAM "net" (in this case, it's a supply voltage of some kind).
You already have an answer from Dave for the third part of your question, regarding C59.
C59 isn't "providing power" at all. It's merely functioning as a bypass capacitor (in parallel with C49, C53 and C285) between that 1.2V supply rail and ground. All of the pins that are connected by that heavy line are connected together electrically.