Is Udemy the best place for a webinar for game devs, or should I look elsewhere?

Marketing & Sales. A lot of entrepreneurs are "doers of the thing" but at some point, you're forced to take the shift and become a "marketer of the thing". Think of it this way: You can have the best product on the market, but it doesn't matter if noone knows about it. Ofcourse, there are so many other important bits I'd love to tell you about - but, start with these and you will see traction, the rest will follow.

If you're bootstrapping, pay yourself less and re-invest in the company. If you've raised money, then pay yourself average salary as you aren't subsidizing and getting more stock (for the $$) as an investor would - so once you raised, then it's a shared risk - don't make the financial subsidy a thing you take on. I see this happen so many times where venture funded founders pay themselves little (ex: $40K / year) to look good, but the truth is you should be making $75K and instead you don't have the financial resources to a) pay off personal debt, b) hire help to be able to have more time to work, c) enjoy life with your partner/family and in turn burn those relationships. Don't make that mistake if you have financial partners as investors. Be fair, but don't take a financial loss every month to save face.

Everything you do (in life and as an entrepreneur) should start with an underlying passion. If you aren't pursuing the things you're most passionate about, you're doing it wrong (or just for the wrong reasons). IMHO. So in that regard, I'd highly recommend reading Simon Sinek's "Start With Why". If you're not up to reading a book, just Google his TED talk as a start.

I am an entrepreneur without a single degree or certification to my name. I'm certainly not anti-education (in fact, I've taught some university classes), but higher education wasn't the path I chose. My question for you is: what type of learner are you? I learn best when I'm self-directed, studying things that fascinate me, and able to either apply or teach what I'm learning (in fact, I think teaching is one of the best ways to learn). So, I've taken ownership of my "education", and I am constantly learning. I read books and articles, listen to podcasts and other audio programs, attend conferences and events, and seek mentors and peer-learning environments. It has worked well for me, but not everyone is built that way. Some people learn better when the education is structured for them, or when they have schedules, deadlines, and feedback (i.e. grades) on their learning. Even for structured learning, college / university is not the only option. There are incubator / accelerator programs, entrepreneur boot camps, mentoring groups such as SCORE - some of it depends on where you are located, or whether you're willing to travel. The bottom line is that education is not optional (especially for an entrepreneur), but there are several ways to get an education. You need to figure out what kind of learner you are to determine what path (or combination of paths) you should take.

I would invest in Instagram advertising. Your target market uses Instagram heavily, so this will be an effective use of advertising dollars. Any kind of social media advertising will get you exposure with these age groups. You might set up a twitter account if you haven't already. You can promote your tweets and get your site out there. Maybe offer some kind of promotion for retweets, or special service or discounts through tweets that only your followers get or are eligible for. If you want an example- @HiddenCash on twitter. Hidden cash gains followers by tweeting out clues to where the cash is hidden in various locations. Best of luck to you!