What is the best reference for motives? I want to learn about homotopy theory on number fields, and I heard that the theory of motives made it possible, so I want to know what is a good textbook for motive theory.
To be honest, I don’t know algebraic geometry (I only read Hartshorne).
So please tell me what is needed to get some knowledge about Algebraic Geometry (SGA? Or other book?).
 A: I would add this as a comment, but I do not have enough reputation to do so. 
While there are certainly more contemporary references, Voevodsky's "Triangulated category of motives over a field" is a place where you can read about motives (https://www.math.ias.edu/vladimir/sites/math.ias.edu.vladimir/files/s5.pdf). His paper with Morel on $\mathbb{A}^{1}$-homotopy theory would be a source to address your interest in homotopy theory (http://www.math.ias.edu/vladimir/files/A1_homotopy_with_Morel_published.pdf). A classical reference is Manin's article "Correspondences, motifs, and monoidal transformations." 
A: A wealth of information is contained in:
Uwe Jannsen, Steven L. Kleiman, Jean Pierre Serre, “Proceedings of Symposia in Pure Mathematics, Vol 55, Parts 1 and 2”. Amer Mathematical Society (February 1, 1994)
This is from before the Voevodsky era. But I think you should know about the classical story before plunging into the derived category of motives. See especially the paper on “Classical motives” by Scholl in the above reference. However, since you mention homotopy theory, you certainly should work your way towards $\mathbb{A}^1$-homotopy theory à la Voevodsky and others.
