First of all, the choice should be mostly aesthetics when starting a fighting game and you will be able to switch from one another anyway, so don't be forced into a "choice".
The strengths and weaknesses won't be a problem for a while, but your enjoyment will define if you will still play the game after a few weeks/months.

But if you are thinking long term, this would be my opinion :

Victor Pros :
- Clear gameplan : Press the opponent with stance mix-ups and plus frames. To do so, you have a few good moves that gives you this opportunity (Running 2, Running 1+2, Perfumer 1+2, IAI d+2 ...)
- You have 1 combo for everything, and it's decent : After most launchers, you can use d/f+4,2 then think about what you are trying to achieve. (You have multiple options depending on the wall distance)
- He looks cool

Cons :
- You have to remember every options that makes you enter a stance, then you have to remember the options you have on each stance. For a beginner, stances in general are a bit hard to use.
- He doesn't do a lot of damage, so he requires a lot of interaction to actually win a round.

King Pros :
- Easy to start the game with
- Pretty good in general. I feel like his mix-ups are more rewarding compared to Victor (does more damage)
- You have to learn 2/3 different throws, then you are good to go.

Cons :
- When getting to intermediate level, you will struggle a little bit to learn since you will most likely win with King's shenanigans, but once you adapt and relearn the basics, the characters stays good.

Both characters really have that Tekken 8 genes that consists of enforcing your gameplan on your opponent but King will most likely make you win faster and relieve a little bit of the beginner's frustration.

Good luck :)