Hey there! I'm skinny fat and I need a piece of advice

So the first thing you're going to need to know about muscle building is proper nutrition is needed and you're going to be needing to eat enough. There is 9 essential amino acids that we need to supply our body with, these are the amino acids that our body can't create. If we workout and don't supply our body with enough essential amino acids, our body will breakdown our muscles to get the amino acids it needs to repair itself. However, the body only uses 70% of the amino acids it gets from breaking down muscle so should we not supply our bodies with enough essential amino acids, we can lose muscle mass. It's really important to be giving our bodies the proper building blocks so it has what it needs to build muscle mass.

If you're going to be going the vegetarian/vegan route, you can look up complete protein sources or all animal products like eggs, red meat, chicken, turkey, ect are complete protein sources which have all 9 of the essential amino acids. How much protein we need is debated a lot. Some people recommend 0.6-0.8 grams of protein per pound of lean bodyweight and some people suggest 1g of protein per pound of lean body mass. I myself am in the middle at 0.8g of protein per pound of muscle mass. Hopefully that gives you a good idea of how much protein you should be taking in. When bulking I usually aim for 150 calories more then my maintenance weight so that my body has more to work with for building muscle but not so much that I'll gain fat really quickly.

At 44 kilograms you are very thin. I'd forsure say to bulk. How many calories are you eating in a day and what are your macros like? The typical sedimentary females average total daily energy expenditure is 1,800 calories a day.

As for learning exercises for the gym, there is a youtuber with the name of Athlean X which I'll link here : https://www.youtube.com/user/JDCav24 He is a pro athlete trainer and physical therapist. Probably one of the best physical fitness youtube channels for fitness. There is a lot of different exercises to learn so I'd suggest going to his channel and looking up exercises for the following muscle groups : Upper/lower chest, shoulder warmup, shoulders, rhomboids, biceps, triceps, wrists, lats, abs, quads, hamstring, calves and glutes.

How you decide to split up workouts is up to you. I do upper body one day and lower body workouts the next day. The day after working out a muscle group, you should rest it as it's still being repaired. Make sure to get plenty of sleep as this is when muscle building mostly takes place.

The last thing to learn is that muscle building is a long term game. If a new person puts on 10lbs of muscle in a year, that's considered fast and every year it tends to get harder to put more muscle on, depending on how much muscle is on your body. Consistency matters a lot and make sure to lift what you should; not what you can. By this, I mean lift weights that you can do 8-12 reps in a set, for 3-5 sets. Doing a bit lighter weights with more sets and proper form will prevent injury and keep you in the gym.

OP, you are at least 10 lbs (if not more) underweight and quite probably not seeing yourself accurately. Please consider going to the doctor and relaying your history to them. Counseling and a registered dietitian can help you see where you are now clearly and come up with a safe and healthy strategy to get to a better place. Until then, please do not try to lose weight.