Cash budgets show cash receipts and cash payments.
So it is the cash received from receivables, the cash paid to payables, and the cash paid or received from the purchase or sale of non-current assets that is relevant.
Paper F5 does not ask you to prepare cash budgets – they are examined in Paper F2 and Paper F9, and you can find free lectures working through examples of cash budgets in the F2 and F9 sections of this website.