Developing a thorough interest in welding is the first step to become an apprentice welder. If at all possible, you should practice at home on your own by welding small projects, but do so only after you have received proper training in the operation of welders and all the associated safety equipment. If you have no experience at all, you can still become an apprentice welder by applying for an apprenticeship with the local welding union. Do not get discouraged if you do not get an apprenticeship once you apply; these positions are quite competitive and you may need to apply several times before securing a spot.
Research as much as possible about welding if you want to become an apprentice welder, and whenever possible, get some job training by working for a construction company or by taking classes in high school or at a community college. Carpentry and metalworking classes are very beneficial, and applying for jobs with a construction company will make you a more attractive candidate for an apprenticeship. Once you feel comfortable with your basic skills, contact the local welder's union to fund out how to become an apprentice welder. It is likely that you will need to fill out an application and some associated paperwork; the union may ask for your high school transcripts, and some unions may require that you graduate from high school first.
If you do not want to join a union and would rather work as an independent welder, another path may be available to become an apprentice welder. You can simply visit local welders in your area and inquire about apprenticeship opportunities. Many independent welders will either be too busy or ill-equipped to offer such a position, but some welders will be more than happy to train you and begin giving you basic welding jobs. Be ready to start at the bottom: you may end up sweeping floors, hauling materials, or performing other menial tasks before you get any relevant training. Take this as an opportunity to show your work ethic and dedication to the job.
Once your apprenticeship is over, you will be prepared for a job as a professional welder. Be sure to choose the right apprenticeship for your career goals, as many employers want an official union apprenticeship rather than one from an independent or unaffiliated welder. The duration of the apprenticeship can range from several weeks to several years, so be prepared for the time commitment.