I'm in Saint-Petersburg

Hi everyone!

Well. I've been living and studying in St.Petersburg for about two weeks.
I live in a student's hostel and share a flat with two roommates neighbours. We had some troubles just after when we just arrived to our rooms because there was were only a bed, a table and a chair for each of us. We had to buy a lot of things to make our  flat dwelling liveable.
Also We've got student travel cards so that we can could go for a trip travel/commute to college at no charge.
Now I've started thinking about sightseeing of this in wonderful historical city. Actually, the city is overfilled full of with a lot of incredible things like museums, monuments (including The Great Patriotic War or, as you might  could hear, The Second World War monuments) and architecture.

So I have a favour to ask those of you who have ever visited St.Petersburg. Please advise me on some famous places you've liked. I'll start my excursions with from these ones. :)
Thanks you a lot. 

P.S. Please don't forget to correct my note. ;)