This is the most common question but there is no straight answer.
The only advice which can be given is time, high quality content, SEO optimization and the list can go on.
This video should help as well from TubeBuddy.
Being a YouTube content creator is difficult. On paper it looks like a lot of fun; you make a few videos, you get a bunch of views and people love you and then you get famous and buy a modest but still kind of expensive vehicle because you want to come across as genuine and not full of...
What helped me grow my channel is to look at trending topics for your niche or channel type. Like, if you do song covers, looking at say the Itunes New Songs chart or YouTube trending can be a good starting point on a song you may want to cover, that people are searching for now.
Just to be clear, using social media to share videos may get you extra views and exposure short-term but not a sustainable strategy to get big. It might actually hurt your progress. The user views you get from FB, IG, Tiktok, and other short-form social media will have attention span of 5 seconds. It will likely wreck your average view times sending negative signals to YT that they should NOT further recommend that video because people are bailing out. The exception to this might be YT Shorts because it is short-form.
The most I will share on any social media account is a link to my YT channel. But no way I will be blindly sharing/spamming my individual YT videos. I want my videos to be recommended by YT and by those who are playing in the YT and Google ecosystem. I cannot have a bunch of outside people (non-YT viewers) who have attention spans of 5-seconds come peek my video and then bail out. Not good for my average view times, the algorithm, or having YT recommend my videos.
You want to encourage views coming from Suggested, Browse, and YT searches. YT does all the work for you when you do your part.