First off, I’d recommend that you redirect this question to ACF’s forum on their website. It is very active and the best place to ask ACF questions. I’d search on there first. If you do need to submit a question on their forum, make sure you proofread your question before submitting and perhaps run it past someone who is particularly fluent in English to make sure it makes sense. This Stack Exchange is just for questions associated with core WordPress.
I’d preface by saying that if there is any way to get those fields from the other plugin to come from ACF rather than that other source, doing this will be much easier. It is extremely easy to set up ACF forms and front end posts…as long as you don’t need fields from other sources.
However if you absolutely can’t add those fields to ACF, you’ll need to do the following (and the ACF forum can provide better detail).
You will create a template and set your acf_form() to ‘form’ => ‘false’. You can then integrate those non-ACF fields into the form template. You’ll need to set up a submit button on that integrated form, since you will no longer be able to use ACF’s built-in submit button.
On the front end, you can then either use a combination of ACF’s native get_field and the_field with WordPress get_postmeta functions or just use WordPress’s.