1)As a newbie what things and category should focus on first?(Black magick, white magick, etc...)
You should read, first. Anything and everything, trying to figure out where your interests lay. Also, just because you read it doesn't A) make it fact or B) make it okay with you. Sometimes learning what works for you is accomplished by learning what doesn't work for you. For example, if you read a fluffy book from Llewellyn publishers and it doesn't resonate with you, then you may want to look more into traditional American witchcraft. Butlets say that the fluffiness does work for you, then you're going to want to see what other books and sources that author quoted, footnoted and included, then follow them.
2)Which types of spells should I focus first?(Love,spiritual,luck, etc...)
You shouldn't be focused on spells at all. You need to be spending your time figuring out what path is even corrent for you.Right now, you've got no sense of magical identity, and as a newbie, this is not wrong. However, before you move into the realm of actually working magic, you need to figure out your place in it.
3)Which spells and rituals are good to build up my magical energy and power?
See above. I'd not tell a Wiccan the same thing I'd tell someone pursuing Aset Ka.
4)What do I need before casting a spell?
A sense of magical identity.
5)How do I clean or purify myself and what do I need to perform this?
Don't even worry about this.
Read. Start with the bigger, more established traditions and see if they even strike a bell. You may find out that this is actually not a religiously-tied need for you. It's certainly not for me. I'm a witch but that working of intent has nothing to do with any deity. Once you've read and you've started identifying the things that do work for you, write them down and look for the trends. This is just like any other learning experience. Use your preferred learning style to start making the building blocks, and you'll see that it does not have to be some overwhelming learning experience.
Enjoy the journey.