Grammar

[oblique wind]

I’m not sure how to phrase it, but I’m trying to figure out… well, I’ll just give examples

„Ich habe Angst davor, dass ich heute sterbe”
VS.
“Ich habe Angst, dass ich heute sterbe”

Which would be correct or more natural? What I mean is, should I add the d-etwas- in the first part of the sentence? For example like in: “wir haben darüber gesprochen, dass er ein Lehrer ist”.

I’m sorry if it’s a stupid question

[young wagon]

It isn't a stupid question at all. So, for "Angst [vor etwas] haben", both are valid (rather like both "I'm afraid of dying" and "I'm afraid to die" are both valid). However, if it's "über etwas/jdn sprechen", you do need the da-compound, because. (Fortunately for you, in this case, it's also just like in English: in "We talked about his/him being a teacher", the "about" cannot be removed, either.) ;)

[modest cedar]

Subordinate clauses with "dass" are important for learning the German language and both examples are ok. But it sounds more natural if you can avoid “dass” if possible.
There are many ways to write this sentence differently and as a little exercise, you should always look for other words and more adjectives to expand your vocabulary.
•Ich habe Angst davor, heute zu sterben.

•Ich habe sehr große Angst davor, heute eines grausamen und brutalen Todes zu sterben.

•Ich befürchte, heute kläglich zu verenden.

•Ich befürchte, dass ich heute kläglich und auf brutalste Art und Weise verenden werde.

•Mir schwant, heute den Löffel abgeben zu müssen.

•Mir schwant, dass ich heute den Löffel abgeben muss. ( “Den Löffel abgeben” is an ideom and translates to „to give the spoon away“. So “Er gibt den Löffel ab” translates to “he dies”. That would be maybe disrespectful, but it does occur in popular literature and also in common usage. You shouldn't use it at a funeral. 🙂

•Ich habe Angst davor, heute von dannen zu gehen. ( „Er ist von dannen gegangen“ means „he just died". Its not an idiom like „den Löffel abgeben“, but another way to describe the death of a person in german.

These are simply a few examples that I would paraphrase as a native speaker.

*Er hat den Löffel abgegeben translates ideomatic correkt to "he just died". "Er gibt den Löffel ab" is ok too, but not the perfekt ideom and might be confusion as a non native speaker i guess. So: "Ich habe Angst davor, heute den Löffel abzugeben" for example.

[oblique wind]

Thank you! I understand it now.