What time of year is the trip?
That's a fairly unusual day breakdown (and list of destinations) for a short first trip (I'm assuming this is your first trip to Italy).
Your first day you'll probably be sleep-deprived and jet-lagged if you're flying in from the US or Canada, so that first day isn't going to be worth much. Therefore, you're giving yourself just one day in Venice vs. closer to 1-1/2 in Milan. Three nights in the Cinque Terre is rather a lot, given the short time in Venice, and I'd seriously consider reducing it to two. I like Bologna, but I would suggest Florence instead.
You may have well-thought-out reasons for the proposed itinerary; it's just that it is rather unusual.
Venice is a lot of fun to wander around. It's not terribly large, and you'll frequently come upon arrows pointing toward "San Marco" and "Rialto", which will help you get oriented. Unless you have mobility issues that make walking up the steps to the little hump-backed bridges an issue, I think you'll get around just fine. Part of being there is getting lost for a few minutes here and there.