How do I build muscle as a complete beginner?

Start with compound movements that work multiple muscle groups at once: squats, deadlifts, bench press, rows, and overhead press. These give you the most return for your effort. Aim to train 3 days per week with rest days in between, doing 3 sets of 8 to 12 reps per exercise. Focus on progressive overload, meaning gradually add weight or reps over time, because that's what actually forces your muscles to grow. Nutrition matters just as much as training. Eat enough protein, roughly 0.7 to 1 gram per pound of bodyweight daily, and eat enough total calories to support growth. Sleep 7 to 9 hours since that's when muscle repair happens. Consistency over months beats any perfect program.