I’m wondering what exactly you want to ship over to your new home in Spain. Nowadays, there’s an IKEA which stocks good quality furniture and many household items eg pictures , kitchen ware, lamps, rugs and all very reasonably priced. Also, pack things into a case and take with you when flying. EasyJet snd Ryanair will transport bicycles too. The cost of driving a van, tolls, fuel, ferry will be pricey so carry them with you on a flight.
You may live to regret bringing old stuff from home once you move as many people have done. Hold fast and think before jumping through hoops at the port.
If totally determined to drive, come over to Ireland and go Rosslare to Le Havre without incurring any hassle or duties. EU to EU