Good idea to start a Tik Tok although I would recommend you keep your options open by having both platforms. You might find the same content that does well on Tik Tok does well on Reels as well, it doesn’t hurt to post them to both but just make sure you don’t have the Tik Tok watermark on your reels.
The majority of Tik Tok users will never use anything else on the app apart from their For You Page, meaning hashtags are rarely cared about. Your content will reach the FYP without any hashtags and if you want to use them I wouldn’t recommend you use too many.
My number one piece of advice for you right now would be to spend more time on Tik Tok, I think people who do well on there are the ones that actually understand the platform and microenvironment it is. Tik Tok thrives on trends so to grow quickly you will want to interact and play on that. You want to find accounts that are similar to what you want to be and see what has worked for them, what sounds and trends they are using, how long their videos are, if they are stitching and duetting, if they are going live etc…
Here is a little bit about how the algorithm works and what it considers given that is unlike any other social media. It considers the words, stickers and filters you use in your video as well as the caption and sound you use. It will then decide who it wants to show your video to and based on the reaction from what it deems your target audience it will decide how many people it wants to show the video to.
If you are uploading high quality make sure you select the upload in 1080p option before uploading. Don’t delete what you think are underperforming videos, sometimes videos blow up 2 days later and the algorithm will limit your reach if you are just going to delete the videos it shares to people. Know that the attention span of a Tik Tok user is extremely low and you will want to hook them in the first few seconds otherwise they will scroll straight past. Pretty much the only way to grow is to appear on the FYP and so you are more at the mercy of the platform than you are on Instagram. Be consistent, the algorithm likes you to upload frequently or at very least regularly.
That would be my advice!