Adding custom fields via shortcode?

Hello and good day to you 🙂

I have heard only good things about MetaBox and now, prior to purchase, I have signed up for the forum in order to dig deeper into the possibilities of MB 🙂

I would love to display Custom Fields on posts via Gutenberg and all my previously tried solutions were either too resource-hogging (AFC with Elementor, Toolset) or generally complicated to integrate (Pods). Only ACF made it easy to display custom fields, but it's limited to simple text-based values. I cannot display relations, which is the main-requirement I'm struggling with.

I'm currently working on the redesign of https://kidsclub-live.de site and want to apply custom post types "Courses" and "Trainers". I need to display each course connected to a trainer. The site should be build with a theme like GeneratePress, Kadence or Neve and only Gutenberg blocks, no pagebuilder and no Toolset.

When reading your docs and checking for relevant forum-posts, I find it very difficult to understand, if MB allows me to accomplish this requirements without applying any code at all. I also have difficulties understanding which extensions I will need for this project, which tutorial to follow, which blog-article is relevant to me. My lack of native-understanding of English is also a barrier here, of course 🙈

So if anyone can explain to me, if I can build this without coding by purchasing the Core Bundle or rather the Developer Bundle, I would appreciate your help a lot 🙏

Thanks in advance and have a lovely day ☀️
Sascha