I think you should start with the earliest published Baki manga. That way, you can follow the evolution of the story and characters in the correct chronological order and fully appreciate the depth and development of the series.
You could begin with 'Tomie'. It's a classic and introduces many of the themes and styles that Junji Ito is known for. Plus, it's a great entry point to his unique horror world.
The general rule is to read manga from right to left. But there are some exceptions where it might be from left to right, especially for some modern or specifically formatted ones. Usually, you can tell by the layout and the way the panels are arranged.
It depends. If you like long-running shonen manga with lots of fighting and character development, then yes. But if you prefer shorter, more straightforward stories, maybe not.