I’ve bike commuted (10 miles) to my office job for the past 6 years. Always bring my shirt and trousers to work each day (and back home at night) in a pannier. Fold trousers in three, and roll shirts. Never felt I’ve been wearing creased clothes at work.
I keep a towel (changed every week) and a little bag with deodorant/hair gel/shower gel under my desk, as I have a shower at work. Bike clothes are hung under my desk during the day.
In terms of bike, mudguards, puncture proof tyres, panniers and dynamo lights make it a lot more reliable/hassle free.