Starting out

First of all I'm sorry that this is probably asked and answered all the time but I checked the top posts and pinned posts and couldn't find it.

I'm adopting a 40lb American bulldog/mutt and want to set her up for success in her diet. I looked into raw feeding a long time ago but that dog passed and I kinda never completed that process. Does anyone know of a website that calculates what nutritional value and how much to feed based on weight and activity?

I also at one point found a post comparing different frozen raw/preportioned foods in cost and value. Does anyone have anything like that. I'm talking abiut things like Darwins, unkibble, etc.

Any advice on food rotation? As in changing brands regularly for those feeding frozen? Is there a true benefit to the health of your dog?

Any other beginner tips are more than welcome!!