Reddit mentions of Royal & Langnickel Disposable Palette Paper 9x12" 40 Sheets/Pad-For Acrylic & Oil

Excellent choice.

On the painting and hobby side of things...

• Citadel Essentials set... Classic Style miniature painting set with glue and snipers to get you started. https://www.miniaturemarket.com/gw-60-12-13.html
  
• Sanding Twigs to cleanup the model during assembly. Get rid of any burs or mold lines from the sprue/packaging. https://durasand.com/products/sanding-twigs?variant=4308092747787
  
• To prepare for painting, after assembly, you'll want to hit that plastic with a primer first. A standard bigbox/hardware store flat white or flat grey plastic safe primer will do. Krylon or Rust-Oleum works good enough. Especially for your first set of models.
  
• Some cheap Pallet Paper to help you work with and thin the paint. https://www.amazon.com/Langnickel-Disposable-Palette-Sheets-Acrylic/dp/B004SYOI0W/
  
• Some cheap throw away brushes to get you started. https://www.amazon.com/Pointed-Painting-Drawing-Acrylic-Watercolor/dp/B0776BTS5B/

Nice job messing up her wooden palette. Nobody uses that for painting, it's intended to hold the materials in the drawer in the portable easel. You're not supposed to put paint right on the palette, you're supposed to put a sheet of palette paper on top of it.