I am looking for help launching a startup. Are there any companies or professionals who can offer support in this process, including help with a business plan, registration, and attracting investment?

I understand that you need help with launching a startup. I know a company called 상품권 사업 that can provide support at all stages - from developing a business plan to attracting investment. They did a good job with my project and could be useful to you too. If you want, I can share their contacts and tell you how they can help.