I'm 330lbs and was thinking about starting to exercise first 1 time a week and as my body get used to it, Add more time to the week... for example if I make exercise Monday and get to 320 lbs and my body get stuck at 320lbs then I add a day to my routine, like saying Wednesday. Will it make a difference?
A lot of people are stuck in the idea that working out is the main course of action when dropping body fat. While exercise is great, dropping from 330 to 320lbs requires you to re-evaluate your diet as a whole and will be the key to your success. The workout routine part is a supplement to that change.
I've seen tons of people who workout on a daily basis and cannot drop a pound of weight. I'd recommend making the workout routine secondary to the change of diet which essentially will make the biggest difference in the world.
Working out more often will make a definate difference. It is alright to start slow, get used to everything first. You don't want to be injured so take it easy when starting.
If you stay stuck at 320lbs though you will need to continue adding a few more workout days to the week OR making the current days you workout, more intense.
Most of all, it starts with the diet and eating habbits. Ff your diet is low in fat & carbohydrates , you will get some insane results. Good luck!