I'm almost the same rating as you, but I have been using programs for a looooong time. If you can get your hands on it, then the best program by far is rybka 4.0. It has a very good database and is probably the strongest of all chess engines to this day.
Chessmaster 10th edition is probably slightly better than Deep Fritz 13, so I don't suggest getting Fritz. Chessmaster also has a few tutorials, opening, puzzles and many more and can be bought at a much cheaper price than most programs. It is a strong chess program, stronger than Fritz, computer (impossible) and many others, but not as strong as rybka, robbolito and (possible) shredder.
Hi. I am an experienced chess player, 1850 USCF rating and I have decided that I want to buy a computer chess program. I have never had a chess program, and I own a Mac, but i can use boot camp to use windows programs. I do not know which program to buy, either fritz 12, rybka 4, chessmaster, shredder, etc. I want a program that can show me my mistakes, opening variants, and databases. I was hoping that someone could give me some advice on what program to buy. Thanks in advance!