You can promote as many affiliate programs on your website as you like.

Over time you will likely be promoting many different products/services on your website and this will take place as your build out content and you see a good match between an audience and a product.

Remember, your role as an affiliate is to connect your traffic (an audience) with a product or service that will benefit them. This will be based on the context and relevance of the content.

Yes, you most certainly can.
Be aware however that it can be challenging to manage a lot of them if you have multiple sites. You will probably way to keep record of what is used where.

As time goes on you may find that some affiliate programs are more favored and have better brands and products and they may have a better trust level with your audience..

Yes, you can join as many as you want.

thanks for the help guys

Of course you can. You decide who you partner up with.

Dave in Durham

Absolutely Walter.

Mel