Hello @Haider_Amin;
Firstly and personally, I’ll never tell you or anyone how much to spend no matter how generic a figure they are looking for. This figure is derived from your operating capital that has been allocated for use on the different avenues that are available for advertising.
For the second part of your question, I would promote all products together only if they are related. If they are not related separate ads for separate products. this will ensure the ads are place in front of the proper viewers.