Completely overchallenged with Divi 4

Anyone out there, who likes to take the time to help me build my webpage? I am trying for more than 2 weeks to find my way through divi theme, fulltime, without big success.

It´s inovative, but also difficult for a non-webdesigner.
I am struggling to find the right settings for responsiveness and maybe I have general issues to understand, what to consider, as the layout looks like all over the place.

I need someone who can lead my project and I will do like he/she says, as I am doing so many mistakes and trying to fix them and waisting too much time in achieving nothing and watching tutorials, thinking of buying more premade layouts and so on. Or wishing to never have bought this life time theme

But maybe let´s face it now?!

- I dont see a possiblity to put rows or modules in other rows or modules. You cannot not easily customize them to any 1/2 to 1/11 you want. The choosen row settings are not always the one I need.
- mobile and tablet settings seem to change both in the same time. Is there a bug?
- I dont find the option to make writing/font with a border
- Is there any module to build cards (like a step by step) booking guidance and that in the end everything is on green or okay? I found the tabs module, but it does not offer to put modules in again.
- a fullwidth image is possible with a divider. But a fullwidth slider not....am I right?
- if you use the paralax effect, can I not use another image position anymore? So I need to crop the Image how it has to look like before?

What do you think about the Divi theme? Is it restricted in a certain way or too complicated until you found out how it works to build super nice looking webpages?