How do I make slide transition more smooth in Keynote presentation?

Two-part question/issue: I have a Keynote presentation with 100+ pictures, and a looming deadline. Many apologies for the questions....No time for a class 😉. Can't find the option under the animation tab for the pictures to appear as though they are zooming in onto the slide and situate with an extended pause before the next slide transitions. I know it should be easy, but I am also having trouble tweaking the transition between slides, which is an animated theme. I figured out how to add music, four songs for the entire 7 minute presentation. While the songs do not pause, the animated theme is pausing between slide transitions. Have tried manipulating the duration of images and slides to no avail.