Ah, planning a day trip around London, nice one! Oxford Circus is indeed a central hub, so it’s a good spot to know. Now, when it comes to the Tube, Oxford Circus is served by three different lines: the Bakerloo, Central, and Victoria lines.
Since you’re starting from Victoria, you’re in luck—there’s a direct route! Just hop on the Victoria line, and it’s a quick two stops straight to Oxford Circus. No need to worry about making any transfers, so you can sit back and relax for those few minutes.
A little tip: Oxford Circus can get pretty crowded, especially during rush hour, so try to avoid traveling during those times if you can. Also, since you’ll be in the area, it’s worth exploring a bit—Regent Street and Carnaby Street are just around the corner and great for a wander.
Hope that helps, and enjoy your trip!