I'm not sure there's a silver bullet, it's a lot of small things that add up to a meaningful life. So my advice would be to look at the small things, and it takes time, you can't change everything at once.
For me, physical health is important (and for everyone really), if you're not physically healthy, you can't enjoy life. There are a lot of aspects to this, exercise, daylight, nutrition, sleep, stress, fun (which contributes to stress-reduction). There are a lot of different things you can do there, and it takes some experimentation to find out what works for you.
Then in the same way, you can look at career, relationships, what you do with your leisure time. My general point is, it's an accretion of small changes, changes in behaviour, that add up and compound, not one big 'eureka' moment.
In terms of general direction. There was a book I enjoyed recently, 'The Van Gogh Blues - The Creative Person's Path Through Depression' by Eric Maisel.
Maisel's idea is that depression can come from a lack of meaning in your life, and that creative people are more susceptible to this than others, because by nature, they seek meaning more.
He had one exercise in the book, which was to write down what constitutes meaning for you, a kind of a personal manifesto in a way. It doesn't need to take long, I thought about it for 15 or 20 minutes. And for me it was generally: learning/growing, relationships with friends & family, having time to relax & reflect, and not being afraid to do hard things.
This helped clarify my thinking. After doing that exercise, I could think, 'How does this activity fit into what constitutes meaning for me?'. So for example, I could ask myself 'Am I going to play some computer games?'. And I would reflect and say 'this doesn't really serve any of my criteria for meaning, so may not be a beneficial activity'. I find this useful in general, in our capitalist society that seems to want to push us all the time to fairly mindless, unchallenging experiences that don't provide long-term meaning.
The nice thing about Maisel's idea is that it's subjective, meaning for you could be a bit different, but it helps to define it.