This year's theme is about encouraging kids to grow their own fruit and veg, so it could be about designing a logo, packaging for seeds or growing kits, handles for growing tools etc.
Also make sure you know about the key styles of drawing, as they take up so many marks, so: orthographic ( plan, end and front view) , isometric (30 degrees), sectional (splitting in half), exploded ( components drawn separately but in relation to each other with dotted lines), sequential illustrations (simple instructional drawings which can include exploded dawings and v little writing. Also perspective ( 3 point- birds and worms view, horizon line and vanishing points). And crating ( draw product inside a box/ crate).
Good luck guys!