The best type of exercise for beginners is the one you'll actually do. Without sounding flippant, the likelihood of keeping up a type of fitness you hate is minimal. But if you find a form of exercise ...
Pilates is a low impact form of exercise that has movement options for people of all abilities. Beginners can practice with just a mat at home or a studio, as well as use tools like a reformer.
Exercising regularly is extremely important and should be a part of your daily routine. With dipping temperatures and air quality still in the 'very poor' category, people prefer to stay indoors. But ...