Oh just a quick word regarding the other points. I agree with the other user. Running, like any exercise, should be about fitness and feeling good. Weight loss can be another thing that helps you feel good and get healthy, but exercise itself is not great for weight loss. Your body naturally tells you to eat more after exercise leading to neutral or even gained weight, if you don't accompany it with good diet.

If you don't want to talk to the trainers at the gym, there might be someone at a local running club, or an online professional coach you could talk to. I can't help you with vetting them or knowing how to talk to them though, I've never done it.