Pick a text-editor, there are plenty (atom, notepad++, sublime text, VScode), whatever you find pleasant. Certain question do not have a fixed answer due to personal preference.
, i would just prefer a software which i would be able to run the codes and preview it even before creating it into a file, is there one like that
what about a site in which you need your users to upload their files for safekeeping, like a cloud,a hosting site with high storage
python offers an IDLE, ideal for running snippets of code before putting them into a script/file. But very few languages hae this.
what about it? You want to create that? I think its above your level