Sure thing Biggest misconception is that you need to run to lose weight. That might help you shed some water weight but that's most of it and that's the number that fluctuates throughout the day anyway. Running is mostly for stamina and heart and lung strength. Muscle requires more energy to maintain than fat so if you start doing some muscle building you will begin by gaining some weight but if your diet is healthy you will eventually start to bleed it off. It's MUCH slower than some crazy crash diet but it's more sustainable because it builds a healthier lifestyle as well. It kind of depends on a lot of factors what or how much you should be eating. But base average level for men is around 2000 calories per day and for women it's around 1800. Now that's average and assuming you arent weight lifting much.
I want to add a disclaimer though. I've never struggled with weight so I've never had to lose it. However, I did want to build muscle last year so I had to adjust my diet because the amount that I normally eat was only good for maintenance. And that was work for me. I had to force myself to eat more than just being comfortable for the day and I had to think about the amount of protein I was eating better. I had to be a calorie counter lol ended up putting on 10-15 pounds of muscle and I still have to keep it in consideration to maintain it even though I can't work out quite as hard as I could back then lol
Additionally, there is a LOT you can do with your body weight without any weights. Depending on the position of your arms you can do pushups that hit different muscle groups. I've done dips using an ottoman and raising my feet up with the edge of a couch lol sit ups from different angles or with some weights (save a milk jug and fill it with it with water. You now have about a 9 pound dumbbell). When you feel comfortable you can do downward facing pushups by putting your legs up on the arm of your couch to target the shoulders. Planks are fantastic for core strength. So are Burpees. You can look on ebay for resistance bands and pick a full set up for under 30$ with a door anchor to broaden your range of things of possibilities (just google "exercise [muscle group like back, chest, arms, etc,....] resistance bands" and look through them. They usually have video guides).
Hope that helps! Feel free to ask if you have anything more specific you're curious about. Best of luck!