Seeking Guidance for Optimizing my TikTok Account!

Hey, I have a few questions about TikTok. I have a music TikTok account where I promote my songs. My questions are:

1. How can I train my FYP (For You Page) to get more visibility? I've come across this topic frequently in the forum.
2. How do I find the perfect hashtags? And what's the optimal size for hashtags, especially considering I'm still a relatively small TikTok account?

I'm eager to learn from your experiences and expertise. Thanks a bunch in advance!