Please advise on best practices for youtube setup of account

I have been here for several years and finally decided to get into video marketing yes way late to the game I know.

Please advise with some short details on best practices you guys are doing with youtube like best way to set up youtube account for business.

I have two accounts a personal and business both are with my name not sure if thats the way to go or allowed with google.

I have never added any videos or used at all had the accounts open for over 2 years.

I made a short video for a small restaurant owner that is my client uploaded it directed me to create a new channel.

I am a bit confused and hope you can give some insight on the whole channel and account set up works.

So we create category type of channels say one channel for all my cpa, affiliate promotional videos and then other channels for my local business seo and promotional videos?

Do I make one youtube account for my local business seo business?
One for my affiliate business?

Or do I just keep it the way it is now one for my personal and one for my general business that I add many channels like one for affiliate & cpa, seo services, one for mobile service, one for all my restaurant clients, one for all my dentist clients and so on?

Last I noticed when I first logged in it showed in my profile my name and email but when I created my first restaurant channel all I see is my restaurant channel info and pages.
Not sure how to go back and see my main business info so I can work off the main account and see all channels.

Do I have to create a channel for my main business that I offer all my local business services and affiliate stuff?

I used that businesses info like email and name or images or logos to brand that main youtube account as well as all the google pages and accounts set up and linked to that youtube account.

Would appreciate your feedback and any tools you use to do all your video marketing that keeps track of KW stats and all video stats when doing video marketing and research. I see around way too many tools selling but not sure what to get that can do it all.