Hello copywriters :) ♡ I have a question please... As beginner copywriter where can I find the B2B emails copy ? And thank you

Hi guys I have a question:) Does narrowing down to a highly specialized niche help in building a strong reputation and attracting clients faster, or is it better for beginners to start with a broader approach? I mean..... You focus on writing emails for a specific service within a specific niche. What do you think?

https://docs.google.com/document/d/1bQKk-3y-IPZJoAKjGQ9d0F6krnh6SpZqPGHJ0CguGvE/edit?usp=drivesdk