Apprenticeships are advertised in the employment section of the paper and there should be a career advisory officer at school who can help you do some work experience in a chosen field. The work experience is usually done during the school holidays and lasts 2 weeks. This gives you an opportunity to try a few different types of job and see if you enjoy the work. If you don't, then you simply try something else.
Career advisory offices can also help you find apprenticeships. If they can't help, then technical schools/ colleges usually do pre-apprenticeships where you study full time for a year and then get a job as an apprentice in a chosen field. The one year of pre-apprenticeship study goes towards your qualification and reduces the apprenticeship to 3 years working for someone. You still do a 4 year apprenticeship but the first year is at TAFE (technical and further education) and the remaining 3 years is at a business/ company.
If you don't do a pre-apprenticeship, then you work for a company and study part time. You do a 4 year apprenticeship with the same company and learn practical hands on skills while there, and you learn the theory during the part time courses.
You get paid while studying if you are working for a company but if you do the pre-apprenticeship course first, you don't get paid during the year of study. However, people that have done a pre-apprenticeship at a technical college have a much higher chance of getting an apprenticeship at the end of the year and most students that complete the year, have a job waiting for them when they finish the course. They get paid a second year apprentice wages because they have already done a year.
And another question, should I get a part time apprenticeship for now if that's even possible or should I just do part time job till I graduate.
There are no part time apprenticeships, only full time. However, if you are thinking about doing an apprenticeship but aren't sure you like the field of work, go to a company and ask if you can do some volunteer work for them.
Most companies take on volunteer workers and let them try the work for a couple of weeks to see if they like it. If you don't like it after a couple of weeks, you simply shake hands, say thankyou for the opportunity to work there, and go try something else.
I would talk to your high school guidance counselor about these questions. I would also google what technical or community colleges are in your area, and I would request to speak to an advisor about career planning there. They should be able to help you with these questions even if you are not enrolled, since career planning involves making the decision of whether or not to enroll in said college.
When I did my apprenticeship it required 6000 hours of on the job training plus block courses. I had worked in a Bread Bakery after school and during the holidays, when I finally decided I wanted an apprenticeship I just went door knocking around all the Bakeries until I convinced one to take me on. Apprenticeships aren't usually advertised in New Zealand.