This has been open in my browser for a couple of days. The short answer: Everything.
And nothing. With hindsight, the best advice I'd have given myself, was to have just done it. It's the advice I give noobs, now. Just do it. Four years ago in July, when I signed up, there were no incubation initiatives and nobody told me about the forerunners of @ecency or @peakd. There was no @exxp.io and I had already been blogging on WordPress for a number of years but was markdown and code challenged. I've learned a bit of both by osmosis.

I ran away for about 6 months and then came back. What kept me was the people. Although there have been times when I've indulged in a lot of this:

The bots and the bullies intimidated me and I wasn't sure how to deal with them. I tried staying out of their way, but didn't always succeed.

Over the years, I've found my niche(s) and even communities that I dabble in. So, actually, it's also about deciding to hang around for the long haul. It seems that @hive.blog is developing longevity. That's good for us all - and thanks in no small way to the likes of people like you, @acidyo, so thank you!