I'm not a scholar, so take what I say with a grain of salt.
In general, according to Islam, actions are judged according to the intentions.
On the authority of Ameer ul-Mu’mineen (the Commander of the
Faithful), Abu Hafs `Umar ibn al-Khattab radiAllahu anhu, who said: I
heard the Messenger of Allah sallAllahu alayhi wa sallam say:
“Actions are but by ...
If you have doubt about whether you made a mistake, follow the feeling that is stronger. If you feel it is more likely that you made a mistake, perform sajdah sawh. Otherwise, skip it. This is for the csee where doubt arises during salah.
If you follow a doubt you are unsure about repeatedly, I have heard tat this is potentially following the waswas of ...
Wa alaikum salaam
I'll answer based on my knowledge of the rules within the Hanafi madhab. There are finer details you probably don't need to worry about too much, so I'll cover the high level basics.
Besides Surah Fatiha, you should recite at least one long verse or three short verses in each ruku. There are details as to what long and short are, but I ...