Workout advice? 5ft 7 - 170lbs - M

I'm wondering if any experts on here can help me.

I currently weigh 170lbs, and am a 5 foot 7 male. I work in an office Monday to Friday, so the only time to work out is after 5pm and at the weekends.

I've been using the Fitbit Flex to get my steps to at least 10,000 every day. I jog for about 15 minutes 3-4 times a week, as I'm only starting back getting fit and that's a lot for me.

I also use the Runtastic Sit-ups, push - ups, and squats app on my phone to help me improve in those areas. I can see huge improvements there already and I've been at them for a week... I do these exercises daily.

I recently bought an exercise mat and have been using it for the above exercises. What other exercises should I include?

My main goal is to get fit, and lose weight to about 150-160lbs. I also want to bulk up a small bit, so what can I include in my training?
Should I get a weight set (cheap one - any recommendations?)

My diet has changed a lot in the past month. I'm using Myfitnesspal to log everything. I've cut out white bread, crisps, most chocolate (sometimes have a square of dark chocolate after dinner), trying to avoid fatty foods, eating more pulses, beans, salads, and fish.

I've been averaging 1500 calories every day, but I'm burning nearly twice that amount through exercise and my BRM. Could this be a problem?

I hope not to make too many mistakes while on the road to fitness.

I think I just need to add more exercises and perhaps weights?

Thanks for any advice

Edit: I've just recently bought a HRM to track the calories that I (hope) to burn.