It's not just regular Russian -- it's very "churchy", as such I wasn't all that clear on what some parts meant, but I did the best I could:
Prayer to the Guardian Angel
O holy angel, behold my humble (?) soul and passions of my life, do not abandon me -- the sinner, but forgive me my trespasses. Do not let the demon of temptation to take hold of me, die by violent means (?); strengthen my poor and slim hand and lead me to the path to be saved. O holy angel of God, the holder and patron of my humble (?) soul and body, forgive me everything, (?) something something my entire life, something (?) and everybody who sinned last night, and cover me into the current day and protect me from various temptations, and if in any trespas I will anger God, pray for me to the Lord, so that he will confirm me (?) something and with honor shows me (?) as a slave of His. Amen
Hope this helps.
P.S. I suspect there's probably a fairly similar Catholic prayer in English -- but I don't know one.