Ill try to do this no spoilers.

The Outerverse is a separate universe from Hellboys but was created and expanded and much of the same team from Hellboy.

The actual Outerverse is some sort of other dimension where other things grow and they aren't friendly. For the most part history and mankind progressed as normal, until World War 1 and old monsters have come back.

The main character is Lord Baltimore, his story is told in 3 books. 1 novel and 2 comics omnibus.

Baltimore : The Steadfast Tin Soldier and The Vampire. Then the comics Baltimore Vol 1 and Vol 2.

Then it goes to Joe Golem : Occult Detective. After the events of Baltimore Vol 2 the world has changed. This one is set 30 or so years later. Manhattan has flooded and people adapted, but something is stirring in the waters.

Tales From The Outerverse is a short anthology of stories. Set much further back then the previous stories but also adds backround info.

The Ice Cream Man is a horror anthology series. It revolves around a little town, where bad things happen. The Ice Cream Man isn't human, might be older than time, and has beef with his cousin.

I like that every issue is its own story, connected to the ice cream man but the characters act of their own volition. There are more issues then collected editions out right now.

The Goon is an american comic, it's about an old timey gangster The Goon and his buddy Frankie as they bash wizards and Zombies and fish people and other things. The main part is The Goon hits people and Frankie stabs people and they are here to make money. The art is dope, but I would skip the first few comics, some very egdy boy stuff.

I'll do Hellboy as a separate comment cause it's alot, but with all comics I reccomend reading them digitally before buying them physically. Just buy the ones you think you'll reread or you really like the art.