I don’t know if I should check on App Store and download electrum from there or I search on goggle?
Download it from the
official Electrum site also in the link hosseinimr93 posted above. Do not use google search for you not to see scam apps. While looking for apps, do not try anything Google at all.
You can see the correct link to electrum website on Wikipedia, for example. Even driving the app's name into the google search. The probability of getting a phishing website is low here, but still, articles there are also written by people and moderated as well. So, for reliability, it will be better to check GPG signatures (information and instructions on this are available on the download page on Electrum website).
Although the possibility of getting phishing sites is low through Wikipedia, it still has the potential to be compromised because as you said it can be written and moderated by anyone.
The simple way I do it is usually to manually write it on paper or a special note and save it.
Or bookmark the original Electrum website.
and pay attention to every letter in the domain really must be the same and nothing is different.
After that look at the file you want to download. The original file will not be detected by the virus.
So in addition to being aware of the domain, you should also provide extra security on the device using Antivirus,