Consistency is key when learning the guitar. In order to keep your motivation, you must always remember why you started playing the guitar in the first place. A good habit would be to practice every day. Avoid skipping a session. It is paramount that you train your fingers to memorize the positioning in the fingerboard as soon as possible. It may be hard at first but when you do it consistently for days eventually it will become a habit. Start with practicing for 15 minutes, in due time you will notice that this time frame is not enough and you will start to increase your time of practice. Ideally, when practicing to be an intermediate player, you would want to practice for at least an hour every day. Take note that you are not only training your fingers, but you will need to teach your ears to hear the tones and familiarize them. This will be vital in the future if you would want to begin your journey as an advanced player. There are really no specific times or calculations that would assure you that you will become good at playing the guitar. The dedication you put into practicing and how you do your practice session would determine your success as a guitar player.