Start reading Chapter 10 Rings of Artin, with an emphasis for now on sections 1, 3, 4, 5.
Be able to raise matrices to powers, and exponentiate matrices, by constructing the ring of expressions in a matrix, and decomposing that ring into a direct product.
An automatically generated source of example matrices is An Atlas of Matrices.
Also be able to construct small finite fields, as quotients of polynomial rings over the integers mod p. Reasonable fields for hand computation include those of order 4, 8, 16, 9, 27, and 25.