For processing your videos I would recommend Davinci Resolve. I am amazed that the company Blackmagic is generous enough to allow users to use a free version which is truly excellent. A few of the high end features such as noise reduction are not available in the free version. YouTube is awash with tutorials that will quickly teach you the basics and then gradually improve your skills.
When I only started working in the graphic design industry, I didn't have much knowledge. I mean suitable applications for work or professional editors that do not require payment, plus that I was so stressed for a while that I had no idea at all. So my creativity somewhere disappeared, and I didn't know what to do because I had orders to do. Then searching more on the internet, I found royalty-free vector images. They served as a good source of inspiration, and I had many ideas after studying those images.