This is my first post in the forums but I have a bit of experience with this.
Keep in mind that I am in the DIY type niche.
First of all, most brands do not care about your subs. Your video views are most important. More specifically, how many views a video gets within 1 week is most important.
Once I started getting around 1k views per video in 48 hours, I started getting contacted by brands to promote their products.
These are usually comission type promos or small $100 to $150 compensations for content creator videos. Videos that I am already posting bit they want to cut them down and use them on their social media and YT to use me as an influencer.
Many of these propositions come with free product also.
I'm talking to larger branding agencies now that have told me once my channel gets to 20k-30k views per video (within a week) I can get linked up with brands who will pay. $1000 to $2500 for 30 to 60 second brand mentions during my videos. (Squarespace and Audible sre being dangled in front of me right now)
There is no rev share involved in this. It is simply an agency linking influencers up with big brands that they have connections with.
This agency is sort of coaching me now and that is my main goal. Again, they sought ME out.
There have been some situations where I reached out to companies relevant to my niche to promote things that my followers would be interested in. Some of these took 1 to 2 months of bugging them until I got to someone at corporate to hear me out.
If you're doing good. Show ambition and most small companies will give you a shot, but remember you are starting your reputation as an influencer. Dont waste your shot.
I suggest posting regularly and doing whatever it is your current subs love you for. Your channel will grow and brands will find you.