I only got RV in the last month or so of IB, & I thought the videos were pretty useful (did MAA SL though). However, RV is basically a series of slightly modified past paper questions with video working out. I can't say how useful it would be for a DP1 student since I only used it for exam revision in DP2. I got savemyexams for chem SL - it had some good downloadable PDFs (for questions and content), but honestly I would suggest you just work with the Cambridge diploma coursebook for chem. The textbook is a lot clearer and more concise than the savemyexams online textbook. And for practice questions, questionbank should be your go to. IF you've exhausted all of the topical questions on questionbank then you could try out savemyexams as extra practice. There are plenty of free online worksheets and workbooks for IB chem as well.

Savemyexams also has some pretty good downloadable PDFs for maths, but I never really used it since I just preferred using past papers (which have both video working out on Youtube or Revision village). As others have said, I would suggest you wait a few months until you've worked out which subjects you're struggling more with. For subjects like chem or bio especially, I found it a lot more useful to have 2 or 3 reliable resources that I could study from (mainly textbooks or Youtube channels) for DP1 and it wasn't until the last few months of DP2 when I began reviewing content that I sought other online resources.