First thing, do the water test to make sure it works. Its in the manual. Basically you just fire it up with water in it to make sure the seals and heating unit work.
Only use tested recipes from tried and true sources until you get the hand of it. Id recommend PRESSURE LUCK both cookbooks and website. Dont use Pinterest recipes until you can tell the horrifying stinkers from ones that work.
An IP cooks in 1/3 of the time at stovetop.... still many people seriously overcook their food in it. A chicken breast takes 6-8 minutes, not 30. Hold off on the urge to overcook.
Always do natural pressure release for meat an poultry.
I use mine for eggs, beans, beets, potatoes, pot roast when im in a hurry, rice and sometimes chicken. Mac and cheese sometimes.
Ive heard negative things about its sous vide capability (doesnt keep even temp, doesnt circulate water) but maybe they have fixed those problems.
I too would hesitate to use it for sous vide, asit has no way to circulate water. Though I like my sous vide cooker, I can get the same results using a slow braise, or pressure cooking, and much faster. The only advantage I see with sous vide is that the food is sealed, and so cooks in its own juices, plus seasonings for an extended time. Again, I can get that same effect by braising in a slow oven, or pressure cooking. The best thing, IMHO, about the IP is its ability to multi task. You can braise, brown, sauté, stew, steam, and pressure cook. Auto settings makes cooking eggs a breeze, as it also does with rice, groats, steel cut oats, barley, corn, and many other grains. Cook up some baked beans, or cassoulet, or split pea soup. You won't be disappointed. Make some short ribs in it, seasoned with fresh garlic, salt, and pepper. The pressure cooker function has them done in 40 minutes, rather than 3 hours in a slow oven. Country style ribs, with a glaze; fall off the bone tender, with flavors permeating the meat. As Jennyemma said, be careful not to overcook foods. Follow the same techniques you would use with any cooking vessel. Your IP replaces many stand alone cooking appliances, with fairly easy clean up. I hope you enjoy it for what it is. Remember, it has many great functions, but is limited, as is everything. Will it bake a cake? It can. Will it make Belgian Waffles; not so much.