Danny, you ask some excellent questions for a newcomer.
You will soon realize that you are saving both time and money using SV cooking and advanced meal preparation techniques.
Successful reheating your frozen prepared meals requires a balance between maintaining your initial degree of doneness and achieving a palatable service temperature.
Most people expect a mouth-feel temperature above a lot of SV cooking temperatures. Therefore we employ a finishing sear to proteins to elevate the food's surface temperature which we perceive as we eat as well as enhancing appearance and flavour. This is easily done with a steak, chop, filet, etc. Those we reheat at or just below your original SV cooking temperature for about a half hour for anything under an inch thick. Thicker than that naturally means using a comparatively longer time, - not temperature.
We get into more challenging culinary territory when reheating mixtures or food in sauces. For them we usually only use advanced meal preparation techniques for thoroughly cooked menu items such as a Beef Stew or Pot Roast in Mushroom Gravy. Restaurants heat those items to 175F or higher for service by immersing the portion packages in boiling water for a predetermined time based on having the same mass or weight for every portion.
That's very important.
For you at home it will initially take a bit of trial and error testing. Do yourself a favour and ensure all portions are the same weight when you package them. If you don't have a kitchen scale, get one. It's one of the basic kitchen tools of a competent cook or baker. And if you don't have a digital instant read thermometer get one too.
Next, always temper ( completely thaw) your frozen portions for at least 24 hours near the top of your refrigerator. Be sure to allow air circulation around your food packages. I use a small wire cooking rack for this.
Start by immersing your food package in boiling water for exactly five minutes, flipping the package a few times to ensure even reheating. Add or decrease that time if the food temperature doesn't please you. Time will vary by mass. Very small portions will only take 3 minutes to reheat.
Above all, keep a permanent detailed record of each of your meals. That's the only way you will learn how to achieve consistently satisfying results. Details means recording the following: food item, food mass, reheat time, final food temperature, and comments on your results.