DO NOT fix your posture. Good posture is not based on anatomical expectation (a.k.a., a skeleton on a chart)--it is idiosyncratic and it will resolve itself with movement. The best posture is a comfortable, functional, mobile posture. If you have any posture needs, see a chiropractor, but don't try to self-straighten. self-straightening exercises are probably in my top 5 stupidest things people can do in fitness, yet they somehow trended a while ago.
1. How far/how intensely are you running? Think of it like this: running diverts some blood flow to your legs, but more importantly, it generally fatigues you. If you're lifting, you want your energy and focus at a high level. Put your energy into your priority.
2. Your question is more general than you realize, but it's a good starter's question. Consider looking up free 5x5 programs online, or possibly free split programs. If you're doing muscle groups together, people tend to divide between push and pull (exactly as they sound), or they tend to put together chest+tri, back+bi, and back+legs. A lot of folks will put deadlifts on a back day, as opposed to a leg day. Again, it's about priority. Lift the larger muscle groups first, and work likes with likes. All you need to do is snipe a free 3 day split program from Google and ask if it's good in here. Better yet, I actually tend to think it's better to do full body workouts 3d-4d/wk starting out, rather than splitting parts up. Just get neuromuscular facilitation and muscular endurance in place first before getting too intense or dividing things up surgically.
3. Sure. You don't need to ask. Just stick em in there. Starting out, be careful about cardio going before your leg day because you don't want tired or sore legs going into leg day, because ideally leg day is the hardest day. That being said, if you go with full body workouts, and you want to do cardio, go with 3d of lifting at first and stick cardio in whenever. Just don't overtrain because you don't want to be too sore and de-motivate yourself. Later, you may not give a crap about pain. For now, think of it as something that could cause conscious or sun=bconscious aversion to a new habit. New habits take 67d to become entrenched.
4. What are you asking? Protein = lean muscle gains and muscle sparing. Your body uses protein for ideal recovery, so I wouldn't skip the protein. If you want to lose fat and gain muscle, consider cutting carbs, not protein. Look into ketosis: properly done, it is muscle-sparing and fat-burning. Ketosis trumps cardio. That is, you lose fat faster on a keto diet than you do doing cardio. Keto burns fat efficiently, sustainably, and without creating carb cravings--cardio invites carb dependency.
5. Yes, but a gym is better. I don't have time right now to list a bunch of exercises for you but youtube and bodybuilding.com are easy portals to that info. But use a gym.
6. Fat loss and weight loss aren't the same thing, but to answer your question, both do involve getting into a caloric deficit. Don't count on your workouts to be the only key to weight loss. You can burn at least a few hundred calories in an hour of a moderate to intense exercise but diet is where weight loss really happens. That being said, lifting weights burns calories and then burns even more calories later as you recover. Running is mostly a "right now" deal in terms of burning calories. You do burn more calories later, too, but it's more about the right now, whereas lifting is really solid on recovery. Alas, it's diet that holds the key. Exercise fires up the metabolism and causes the body to recover, but diet is where you can very easily control weight loss.
7. It depends on your chronotype and other factors but most people do better in the morning. Just don't wake up an hour earlier than usual, feel stupidly tired, and then think you did something smart. Workout when your energy are focus are high.
If you need other help, PM or post. Don't just try to transform your life--do it. That is, don't ask for permission to make yourself great. I'm in the transformation business. Here's how it works: find your passion (your "why"), and then figure out how to make change happen by doing stuff. Don't dive into too much theory unless you're taking action at the same time. Knowledge is indispensible--don't get me wrong--but practice is the key. Action, action, action. You learn better through action anyway and action ignites curiosity and helps you test and define things. Don't depend on others for your answers. I've answered your questions but I hope you will just do what you are ready to do now and make yourself ready for more. Find your won answers ASAP. I get that asking questions here is a way of being resourceful but I encourage you to refine your thinking, just do something, and see how it goes. That way, when you ask your next set of questions, they will be more fine-tuned

I hope you will kick some ass
