ReactiveUI is an open source project that is community supported by people just like you. We keep a bunch of curated tasks specifically for new contributors which are a great way to get started with open source. They also provide a fantastic avenue for getting to know the ReactiveUI maintainers.
We have our very own Slack organization which contains some of the best user interface/reactive extension developers in the industry. All software engineers, young and old, regardless of experience are welcome to join our campfire but you'll need to send an email to firstname.lastname@example.org with the Email address you'd like to be invited, and we'll send you an invite. Sit tight, it's worth it.