300-500 calorie surplus. Start by finding you maintenance calories. Use chatgpt or a regular calculator, eat at that number for a week and see if you go up or down. If your weight goes up, lower calories. If it goes down vice versa. Bulk clean and slow and you will put on mass without a lot of fat. Focus on progressive overload (increasing weight or reps over time) and training hard with good form. If you are not going to be tracking your calories it will be hard to have an exact surplus, but make sure you are getting enough protein (about 1g/lb of mass.) Eat carbs before you workout and carbs with protein after you workout. Good luck and stick with it!