What is the best solution to be able to have users sign up on a forum blog type of integration where users can reply to blog posts, or create new ones for all users to be able to share and get idea’s from one another.
Has anyone used any system that works well?
Like a blog where other users who have signed up can make comments or create their own posts.
You could use an external forum like Discourse.org. The same Webflow are using. Otherwise I would say you need/should go down the WordPress route with front-end post submissions using for example CalderaWP form.