If, and or functions used in stock control

I would appreciate help using IF, COUNTIF, AND, OR functions The exercise is around stock control and I've attached the stock number spreadsheet which is the basis of the exercise. I know this is really easy for all you but it's making my head hurt! Thank you in advance

1. Using IF function amend spreadsheet to show (a) which products need ordering (b) how many items needs to be ordered (think we've managed these - F&G)
2. Using COUNTIF amend stock list to work out how many different products need to be ordered , eg how many different type of bag (not how many of each).
3. the suppliers will not allow orders for small quantities of products. Orders must be in multiples of 3.
(See colums N & M for details ) . Usee NESTED IF function to amend your solution so that it shows the quantity or order for each product.
4. USING OR / AND - exclude any orders that are for products in PINK.
5. USING OR /and -products in blue are proving popular, so even if you already have enough of a product order extra if it is blue. Amend spreadsheet to show which items now need ordering to include anything Blue.