Victoria has 2 stations?

If it’s a train ticket then it the train station you need. The coach station is for buses.

There are actually 3 (sort of). The Coach station (which is for buses only). Victoria Station on Victoria Street, that is for trains and tube (this is the one you want) and the newer Victoria Underground station (that connects to the other VS, but for tube transport) on Cardinal Place.

Here's a photo of the Victoria Station you want. You will go in the entrance to the building there. https://media.timeout.com/images/106064086/1920/1080/image.webp

Just a warning that Victoria Station (the aggregate of all those Mardee talks about) and its environs may well be the single most confusing area in all of London. The Station has miserably poor signage, traffic outside is dreadful and it's hard to get accurate help re: "how do I get to where I need to be?" I think it's because the place confuses even native Londoners and the people who work in the darn place.

Don't overthink it. For a train ride, go to the train station. For a Tube ride, go to the Tube station. For a coach ride, go to the Coach Station.

Most native Londoners, and certainly anyone who works at Victoria knows that the left hand side of Victoria railway station is for trains to Kent (basically the single digit platforms) and the right hand side (the double digit platforms) for trains to Sussex (essentially those going through East Croydon or Gatwick airport).
With the new coloured departure boards with directional arrows it is even easier to find your way around.
Platform 8 (on the Kent side) is where the memorial to the Unknown Warrior of WW1 is, as that is where his train from Dover arrived (off the boat from Boulogne) en route for Westminster Abbey the following day. I always try to make time to visit the memorial when passing through Victoria.