I can't tell you where a good place to buy a starter kit would be but the numbers are the smaller the number, the longer the hair. In other words, a 3 blade would give you longer hair than a 5. Good luck! You are brave!
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"If you have men who will exclude any of God’s creatures from the shelter of compassion and pity, you will have men who will deal likewise with their fellow men." — St. Francis of Assisi, 1181-1226