WMM2 has scrolling titles and credits as part of it's standard build.
It's not under effects.
If you hit the blue button on the toolbar called "tasks" it gives you a drop down list on the left hand side of the screen under selection #2 (edit movie) click the words that look like this.
Make titles or credits
pick where you want your credits (begining/end) and choose Change the title animation
there are many "text effects" in there