There were many occupations in colonial times - butchers and bakers and candlestick makers and hatters and coopers and printers and cobblers and wheelwrights and all kinds of smiths and more! The most important occupation was that of farmer.
Like Father Like Son: Many businesses in the New World were family businesses. Fathers taught their sons the trade they knew. As the population grew, more craftsmen and workers were needed.
Indentured Servants: To help solve this, people in Europe were offered an opportunity to purchase their passage to the New World by signing a contract that said they would work for a certain number of years as a servant. As part of their contract, they were provided with a place to sleep, food to eat, and taught a trade. Most contacts obligated them for 7-14 years, which was considered a fair amount of time to pay back the cost of the passage, their room and board, and their training. When their time was up, they would be free of this obligation. Some people signed up for a specific type of work, like learning to be a baker or a blacksmith. But contracts could be bought and sold.
By 1775, it is estimated that about 400,000 indentured people had arrived in the colonies. People became indentured in different ways. Some were eager for a new life and willing to work hard to get it. Some people were offered the option of becoming an indentured servant instead of going to jail for a crime they had committed. Some people were kidnapped and shipped off to the New World where they were purchased by the highest bidder in the same manner as slaves were purchased.
Not all owners were cruel. In fact, very few of them treated their indentured servants poorly. Still, about 20% of indentured servants were unhappy with their situation and became runaways. If captured, they were returned to their masters and had to serve extra years on their contract as well as other punishments.