Scotch tape is a transparent tape, called Sellotape or sticky tape in some areas.
If the tape is too wide, have an adult trim the tape with a pair of scissors.
Always wait for one color to dry before you add another color on top of it. A clear polish after everything is dry will make it look glossy.
Surround the fingers around your nail with more tape to protect them from the polish. Be careful not to overlap the tape with your fake nail, or you could tear it off. Dip a thin straw in nail polish and blow through it while it’s just above the nail. This will splatter the polish over the fake nail. Repeat with other colors. Since the tip of the straw has polish on it, you’ll want to put the next color on a plastic plate or bit of newspaper, then dip the straw in that instead of directly in the nail polish bottle. When you’re done, let it dry, then remove the tape protecting your fingers.