Power-Up Pods can be found towed behind boats, on the track during races, and in the air after many jumps (shown in screenshot).
Level 1 has several but I would recommend playing until the first "Collect Pods" level (level 2 if you go left in the first race or 3 if you go right) and saving at the start of the level. Hit as many jumps as you can, collecting the pods. When you hit the finish line just reload the save and repeat as necessary.