Even the AGPL allows forking. And there's nothing to sell actually.

If you have plans to self managed solutions and don't want to compete with other players doing the same, look into the source available licenses (BSL and others). They are not open source though, so please don't add those two words to your website.

Open source will get you more traction initially since some people won't even consider proprietary solutions in some cases. But it comes at a cost.

If this project is not expected to be your main income, maybe open source would work. Depends on your goals.