Race week is for arriving rested and prepared, not proving your fitness one last time. The training you missed cannot be recovered with a hard session now. Follow the taper in your chosen programme and resist adding workouts because you feel nervous.
Sort the details early
Check the start time, bib collection, transport, bag drop, course cut-off and aid-station arrangements on the organiser's own information. Plan how to get home afterwards. Put your tested shoes, socks, clothing and fuel together before the final evening. A new pair of shoes or an unfamiliar gel can wait for another training cycle.
Keep meals familiar
Eat enough to support recovery and avoid deliberate crash dieting. If your programme or dietitian includes a carbohydrate-loading strategy, follow that rather than improvising a huge feast. Practise your race breakfast during training, and use the same timing on the day. Keep unfamiliar restaurant meals and new supplements out of your final preparations.
Write a flexible race plan
Choose an opening effort you can sustain, not a pace borrowed from a faster friend. Plan walking breaks if you practised them. Check the forecast and adapt expectations to heat, humidity and how you feel. Carry only fuel you have tested, and know where you can access fluids without assuming every aid station stocks your preferred product.
Make room for changing the goal
Illness, injury or dangerous weather may mean postponing, withdrawing or stopping. Chest pain, faintness, confusion or severe symptoms need medical attention, not a motivational speech. After the event, walk gently as comfortable, eat, rest and return to training gradually. Completing one race is not a reason to skip recovery for the next.