Are you playing 6max or Full Ring? That will effect what advice we give as well.
First: I wouldnt worry about buying a calculator. Just learn basic
odds from a chart (look in our strategy articles section at top right of your screen).
2: 5k
hands isnt that much but biggest thing is get your VPIP and PFR closer together. They should be within 3-4 pts of each other.
3: cbet more, steal more, 3bet more.