What should I do for fat loss?
HIIT is more efficient at burning fat than steady-state cardio. That means sprint>rest>sprint>rest>sprint>so on beats a steady jog for energy burned/time.
The best form of fat loss however is to eat less, simply because it is far more efficient to lose fat through reducing food intake than to burn it off through exercise. Your body is built to conserve energy by being efficient, including while moving, not expend it - so it kinda speaks for itself that reducing energy intake is more efficient than trying to spend it. Calculate whether you eat too many portions, whether your portions are too big or both, and then work on reducing your eating a little more than last week, week after week.
Something critical to the success of this is to not underestimate or deny the amount you eat or how fat you are, which is common. A tip is to swap out simple carbs like candy, beer, soda, etc. for complex carbs that may or may not contain some fiber like sweet potatoes, oatmeal and vegetables like spinach.
Combine with HIIT and you will see changes coming soon. I would recommend focusing on losing fat first and building muscle after you've become lean already.
What routine should I use as a beginner?
I would first of all recommend correction exercises which fix the posture misalignments you are likely to have. Something which goes well with that is getting an MRI/seeing a chiropractor. In our modern day civilization, this most likely means:
1) Abdominal training which doesn't involve the hip flexors (the plank is good) and glute work (hip extension), to fix anterior pelvic tilt
2) Back training that focuses on upper back extension (remember to extend your neck) as well as scapular retraction and depression (rowing can be a complete movement for all three things but you can also hit the spinal erectors specifically with back hyperextensions), to fix forward-rounded and slouching posture
3) External rotation of shoulders (and maybe hip too) to fix forward-rounded and slouching posture. You don't need to do rotator cuff exercises, just do things like rowing but with an (non-extremely)externally rotated grip.
Want a superhero posture? then repeat after me: Glutes, Back, Abdominals, External Rotators. You don't need to make these muscle groups the main focus of your strength training but you should be working them frequently with light weights for the purpose of re-aligning your body's posture, and consciously flexing those muscles more in your everyday life.
Okay, so now we come to the part your brain was actually thinking about instead of that "posture" garbage. Who cares?! Give me big arms, Attack Formation!
Well, there are no secret exercises and no magical routines that will explode the muscles you want. People who say so are usually either ignorant, on steroids, and/or have an agenda. Aim to work the muscle 2-3 times a week depending on how well you are recovering and what you prioritize, one time a week in the beginning of working a muscle if you feel like it's been killed and you can't use it again.
Pick the exercises that work best for you, not for someone else. Do not keep doing something that causes you pain, and look into common causes of pain & long-term damage and how to avoid them whenever you start doing an exercise. If you want a list of things which commonly cause pain and damage immediately and over time for various common exercises, just ask me.
