Train Tickets Europe

I Am Planning To Go To A Few Countries In Europe This July.

The Countries I Definitaly Will Be Visiting Are, Holland, France And Spain.

I Will Most Likely Visit 2 Cities In Each Country And Spend Around A Month In Total Travelling.

My Question Is What Type Of Train Tickets Will Suit My Rough Itinery?

Where And When Do I Buy Them?

Do I Get A Pass For Multiple Countries? If So How Does It Work?

Thanks