Hello

GK syllabus itself is huge and you cannot predict questions coming from any specified part. There's no doubt that reading newspaper daily is the best source for GK

Now coming to your second question, I can answer for StudyIQ only, the videos they upload are in English as well in Hindi, wonderfully explained. So, it's definitely a wonderful platform to keep yourself updated with the current news and happenings. A lot of websites too provide monthly pdfs, if you want you can refer that as well. But, most important thing is going through previous year paper as well as giving mock tests on regular basis.

Thank you!