As an Orthodox layman I consider myself fairly well versed with some of the teachings of the Church so I will state that the below is the position of the Church, but I can always be wrong so I humbly solicit correction from others if I misspeak.
Both your questions(Orthodox positions on chronological length of the creation period and the theory of evolution) is that the Church has no dogmatical stance on either issue. I think if you polled most hierarchs, clergy, and layman, you would find that most hold a longer creation timeline and that many if they follow evolution at all, hold strictly to microevolution and not macroevolution. However as this is not a "dealbreaker" you will find varied Orthodox opinion.
You may find as you investigate Orthodoxy, that unlike many forms of Western Christianity, that we feel no need to codify that which is not viewed as essential for salvation and living life in Christ through the Church(which is of course the verb form of salvation). God Bless you and I hope you find the answers you seek.