IndieWeb and ActivityPub can play well together. I for example am part of the IndieWeb using my blog. But my blog also supports ActivityPub, so that people can follow it using Mastodon for example and ActivityPub replies get translated to webmentions. However, it's a very custom implementation and I need to figure out how to make it available for use by more people.

Probably the easiest way to participate in both the IndieWeb and the Fediverse is by using Wordpress with a couple of plugins installed.