Like any new discipline, especially a discipline where you are likely to feel some resistance to continuing with it, it is best to find a time when you can make meditation part of your daily routine. It is also best, at first, to set the time and place to allow for a minimum of distraction during your sessions. Basically, any time at all that you can set aside consistently is the minimum requirement. Ideally, most meditators try for twenty minutes morning and night. Choose a position that you can maintain for the desired period without undue discomfort.
Some people suggest dim light, some suggest a slightly cool room.
Traditional Buddhist practice is to meditate with eyes open but unfocused. The bottom line is that if you keep it up, through the times when it seems incredibly frustrating, you do get to some very useful insights and a new level of discipline of the mind that can only help you on your spiritual path and in your practice of magic. If the frustration gets to the point where you give up on it for a while, stay open to the idea that you can try again with a different technique at another time. The rewards are subtle but powerful.