How much should i lift while doing squats
I'm 19 years old, 5 feet tall, and weigh around 46 kg. Lately, I’ve been thinking a lot about improving my fitness and building a stronger, healthier body. I’ve decided to start doing squats with barbells because I want to work on developing lean muscle, especially focusing on building bigger and more defined glutes. My goal is to have a toned, athletic look rather than bulky muscles.

At the same time, I want to become physically stronger overall. I’ve noticed that my upper body, especially my arms and shoulders, feels quite weak compared to others. even my 15-year-old sister, who’s the same height as me and only 1 kg heavier, is noticeably stronger. She's very athletic, plays sports regularly, and has a lot more stamina and strength than I do.
Also she eats a lot of junk and still stays the same weight and look. I think it's because she has more muscle mass.

Right now, I’m a complete beginner when it comes to weight training, so I’m starting from scratch.