new to magic

im confused tho because i use light spells and use white magic..... my grandfather tells me my energys are high in the day ..... also there at there peak at 12.00pm when the sun is highest..... does that mean im destant to use white magic and will black magic conflict with my energy?... also the spells i use say the helpers of the spell is at dusk and outside... but after dusk my spells has weak to no efect at all...... and i have tamperd with dark magic and i often feel weak frm just saying the spell and barely concetrating on it.... does that mean i am restricted to light and white magic spells? and alot of ppl say its unusuel i draw my energy from the sun....... im just lost and confused