Determined to be healthy and happy - lifelong life style change starts NOW

Hi everyone!
I'm a 25yr old female who is determined to make a healthy lifestyle change for ME. I have two kids under two years apart and for the first 6months after my second was born I was very hard on myself and kept yoyo'ing in my diet and lack of exercise. Well I knew I needed to start working out again and being healthier sooner rather than later! I was a very fit -4x a week (volleyball, tennis, running) woman before I got married and I want to get back to that! Sports and working out brought me a lot of joy and it's time to put myself FIRST! I currently weigh 177lbs and would like to eventually get back down to 140lbs as my first goal- I have been getting back into working out for the last two months and I want to train for a half marathon this spring and actually finish Im hoping to find friends on here who I can help and who can help me be accountable for working out and eating right!