I'm no expert, but some UK-oriented suggestions for things to do in response to ongoing genocide and famine in Palestine:
- Change your bank account, there's a UK list of complicit and non-complicit banks here: https://www.ethicalconsumer.org/money-finance/israel-deadly-investments - e.g. it seems Barclays, HSBC, JP Morgan, Lloyds, NatWest, and Santander are using your money to finance the military and settlements
- E-mail your MP https://www.map.org.uk/campaigns/stop-uks-complicity-to-end-israels-atrocities-a
- Donate, I'm not sure what's best but maybe to a mutual aid organisation like the Sameer project https://chuffed.org/project/113222-tent-campaign-the-sameer-project or Dahnoun https://chuffed.org/project/115245-dahnoun-mutual-aid
- Boycott e.g. Google, Amazon, Booking.com, Airbnb, Expedia, Teva, Chevron, Intel, Dell, Siemens, HP, Microsoft, Carrefour, AXA, Reebok, Disney+, Sodastream, Re/max https://bdsmovement.net/Guide-to-BDS-Boycott