If I insert the same citation, I see Id. however, I want to change it in Italic style. How can I do that?
Also, can I use supra instead of id?
Also, I don’t want to put dot (.) at the end of the sentence. However, it is not possible to erase anything from the automatic generation of citation. My citation always brings dot at the end. How can I erase it?
For example,
I see dot, like this:
Id., at.
I don’t want at or dot. However, I don’t know how can I erase at or dot,
Also, whenever I cite the footnote, automatically the bibliography is produced. How can I stop it?
All those are dictated by the output style and templates, either in the footnote or in the bibliography sections for each reference type. Without knowing what output style you are using, and looking at it, I can only guess that the template is not correctly linking fields with punctuation and words, and italicizing the automated Id insertion. The bibliography inclusion or not is also a setting in the output style you are using.
Editing output styles is in the manuals that can be downloaded here: