Some legal resources - in no particular order.
Information for people in Scotland affected by the crisis in Ukraine - Scottish Refugee Council – SRC information – we also have a direct helpline for anyone seeking advice or support and that is 0808 196 7274 – this information and more is included on the webpage
‘Homes for Ukraine’ scheme launches - GOV.UK (www.gov.uk) – CSS information from Home Office
After getting refugee status, your guests should automatically receive an NI number in the post but given the likely numbers coming into the country this might be a bit chaotic. If nothing arrives, try: https://www.gov.uk/apply-national-insurance-number.