the whole purpose of making a website is to make money with it. Do you have monetization installed on your site? If not, THAT is your next step (put some Adsense ads on it, or promote an affiliate product, build a mailing list that you can advertise to, etc),
If your site is monetized the next step is to obviously drive traffic to it. Traffic is the lifeblood of making money online. ZERO traffic = ZERO money. As simple as that.
And the best way to drive traffic to your website is organically. Organically means methods through which people discover your website naturally, like google, youtube, facebook, forums, blog comments, etc. Just pick a method that you enjoy / feel capable of using until you constantly start making money with, then expand to other methods to increase your profits.
I can't help you with youtube and social media (facebook, twitter, etc) since I hate both of them with passion and so, I don't know much about them. But I can help you with SEO by telling you that to drive traffic to your website with SEO (google, yahoo, bing, etc) you need 2 things, and 2 things only:
1) content
2) backlinks
Since your website is new I would focus on creating content for several months, each day if you can. The sooner your content starts getting picked up by google the better, obviously. At the same time with creating content, you also need to start building backlinks because, ultimately, backlinks are what will get your site into google and keep it there.
Sure, there's no exact science on how to do this because google changes their ranking factors quite often, and each website, in each industry (niche) will rank for a particular keyword totally different (some keywords rank from day 1 and without a single backlink, other rank after 1 year or more, and only after constant backlinking). But the important things is that fresh content + quality backlinks are what gets your site to the top of google and keeps it there.