Two comments from me to add to the above
1. Get a lesson asap - its invaluable to set your posture and technique on the right road. There are a few DB players on BassChat that teach in the London area such as jakenewmanbass (I can recommend him strongly) and chrkelly (not had a lesson but super nice guy)
2. I gig DB in my band and cannot play arco for toffee - I don't feel the need to learn either (although I do have a bow) as the music I play (folk/blues/country/flamenco) simply doesn't require it. Some strings don't work for playing both arco and pizz and an arco setup usually requires higher action than a pizz-only setup, although personal tastes can obviously vary widely about string height (some like it Ray Brown-style high to get more plucking volume, I prefer it low as I have to play a lot of fast lines). In short, learn arco if you want the broadest DB experience but its not necessary for many types of music. Your call here