I have finally decided it is time to stop being satisfied with simply hating myself and body and do something about it. The million dollar question of course is where to start

? This is my first post to the boards and if it is more suitable for the diet section please let me know. There are so many exercise regimes out there and options but with having had such a lack of physical activity for so long I thought maybe some others out there would have suggestions as to something to start with?
To give you a little information, I am 26, 5'4 and scared to weigh myself but am guessing I am about 240. My boyfriend and I have both gained a substantial amount of weight in the past 2 years together and are ready to make a lifestyle change. It is affecting everything from the way I feel to our relationship.
Any thoughts and ideas are greatly appreciated. Thank you!!
-Megan