50 squats and cycling in endurance/cardio. If you start with almost literally no muscle then you might build some from it but nowhere near the amount you'd want. Your muscles grow when they are continually challenged to lift more weight for a lower number of reps, lets say 12 max but it's grey. You need more weight than you think to do that which is why people join gyms- to get access to enough weight.
I was talking to a woman at the gym the other day, she's been lifting for a few months. Firstly, she couldn't believe she looks better heavier and (with somewhat dodgy form) she was squatting 60kg for 5x5 and deadlifts 75kg x5. Those are thing you need to do for leg muscle and weights you can expect to reach fairly easily.
If you will go to a gym then look up ice cream fitness 5x5, it assumes you are a guy so half the weight added and consider starting with less than 20kg on overhead press. Gaining muscle is gaining weight s you need to eat a calorie surplus, just a few hundred a day- men get 500 as a suggestion but you can't build muscle as fast so think more 200-250. It'd be nice if we could say eating healthy helps but it doesn't, so by all means do but it's calories and protein that matter. You don't need a million g protein per day, just get a decent amount in each meal.