Asking for advice

I'm a creator with 2-3 clients currently. My clients like me for my video and infographics outputs. They also like how I come up with lots of content ideas. But the difficult part is getting people to watch them, especially when it's a newly created account. I understand that it's literally going to be pure silence upon creation of the account. How do you guys bring audiences to your pages? I've tried the follow-unfollow strategy but my clients don't like that. I'm currently very dependent on hashtags and spending a lot of time on engaging with other posts but they don't really convert to traffic.

Also, do you first focus on a single platform or it's doable by promoting on other platforms simultaneously? Thanks in advance!