First thing is to farm the treasures, unless you already have them. If you do not, remember that not getting them will make every stage much harder than it needs to be. For the rest, well...I can only do so much without having a clue on what chapter you are on or your levels in general, so all I can say is to use 3-4 general meatshields (no rover), Voli (unevolved) and some stuff like Macho Leg, Paris, Surfer or Drama. If they push too hard from the beginning, use Volta in evolved form and more meatshields of the cheapest kind instead of eraser.
You mean with a fresh account or an old one? If you plan on restarting with a new account, I suggest you to consider returner mode, as that would save you hours of tedious farming, otherwise I don't really know what to tell you, just play however you like.