Hey, so some people such as my self like to visualize a white ball around them filled with light and pure energy to block out all that negative energy. Also, I recommend getting some Black Tourmaline a very powerful protection stone in my personal opinion is it is one of the best stones for protection. Putting four tourmalines in corners seals the room with a protective shield and blocks out all negative energies and unwanted energies. And if you don't really understand or know how to visualize I'll link a link to help with that!
And you don't really need tools or anything like that to learn how to protect yourself from negative energies all you really need is to learn how to visualize!:D
Learning how to create a personal energy shield to protect you from unwanted things is an important part of working with magic. There is an article I posted about it at - http://www.spellsofmagic.com/read_post.html?post=871165
Protection is important, from dangerous energy, spirits, or just draining people. You can use your method of protection whenever you feel you need a boost, psychological or even physical.
Making a shield with energy is a great idea, visualizing a shield (of whatever color seems the most accurate for you) being attacked in vain is quite a powerful moment.
Balls or encasements of light or representations (forming bricks, bodyguards, energy walls, anything from a single defender to a full on army) seem the most popular. Certain crystals and herbs also can help:
Amethyst is my second favorite crystal for protection. I've always wanted to get my hands on obsidian, but I've yet to. Both are wonderful for protection, amethyst is better for your in general protection and obsidian is great for the more "psychological" attacks (energy draining or negative energies for example)
Herbs and other things like symbols are also great, especially if you want to protect an object you can't give a crystal or an area that might be affected. Sage and salt are the most cliche, but be careful with sage (there are a few forms, but white-sage is the best for protection. The others tend to be great in a crisp salad or for an unexpected kick in your seasoning XD)
Cedar is also good, if you like the smell or if you can work outside. I never got used to the smell and hate that I have a whole vial of it practically untouched. I literally will use anything else if I have to, mint or clovers or ANYTHING, but cedar, but it could be for you. People tell me that they like the "strong woody smell" but I just don't see it XD
Last of all, the thing I find helps me the most: not letting things get you in the first place. I don't mean don't practice, or become a saint and only practice a few, selectively safe things. No no. I mean not letting the people you meet get you, knowing who is an energy drain, who is using you, who is controlling you, etc are all important things for everyone to know. You can really protect yourself in magic if you can identify who is hurting or can potentially hurt you, because it will identify dangerous energies. Also, by already being prepped against negative energy, you have your first layer of defense already set up. You should probably set up a second layer, because some things are really dangerous, but this will help you in case you are caught completely off guard and need a moment to visualize.
Protection is incredibly important. I'm glad you know to start there, not a lot of people do.
So good for you! And good luck!