After the opening cutscenes, have Olimar use his whistle 
to call the red Pikmin off the Dwarf Red Bulborb. The Pikmin will come back to you under your command. Throw the Pikmin 
on the Bulborb, then approach the bag. The ship will inform you that the Communications Link with Louie is now available. Switch to Louie 
and walk up the hill. Approach the large dark red object, the onion. It'll sprout out and drop a seed, wait for it to grow, then pluck it with . Throw it at a small pellet with the number 1 on it, then wait for them to bring it back to the onion. Pluck the two new Pikmin that grow after. With more Pikmin, you can pick up heavier objects and pellets, such as number two pellets. Continue doing this until you have 11 with Louie. Throw all of Louie's Pikmin into a group, and do the same with Olimar. Unite the two and then return the dwarf bulborb to the onion. You should have 20 Pikmin. Find the battery, and throw all of your Pikmin at it to carry it. Once it reaches the Ship, it will appraise it and name it Courage Reactor. Day 1 will end.
On day 2, propagate plenty of Pikmin, around 36. Crush the second bag. (Notice the Pellet Posies with 5s on them. Their pellets take 5 Pikmin to carry, and produce 5 Pikmin.) Pass the second bag. Beware the enemies, they can eat your Pikmin. Defeat the Dwarf Red Bulborb and carry it back. Then get all your Pikmin and sneak behind the Red Bulborb. Throw Pikmin on its back really fast. It should go down quick. Grab its body and the pellet, then grab the crushed can (Utter Scrap). By now you should have around 70 Pikmin, excluding any that were eaten. Bash the wall down, then grab all your Pikmin and enter Emergence Cave. Once you leave with the special part there, the day ends.
You will be able to access more in this area once you have all five types of Pikmin.