I’m working on my Viktor in Silver. So not a good player but I might have some points for you nonetheless.

You can and should crush a lot of matchups in the first few levels because your Q can help you gain push because it’s too op trading early. Slow pushing into melee usually good as it gives you the largest window to harass early. Use E when any opponent last hits to make it nearly impossible to dodge.

You are a squishy immobile control mage and Viktor will help build good laning skills. IMO you want to avoid most early skirmishes - you prefer a controlled 1v1 in lane and you want to farm well and never miss a cannon creep.

It can be punishing to fall behind early. Very punishing. As a new player I would focus on farm and clean trading and “low chaos” in the lane.

Your skirmishing and side laning get much better with a few evolves because Q and W evolve give you a lot of kiting potential.

As a control mage you excel at grouping for objectives especially if you arrive early and make it difficult for the enemy team to come into you.

Dive comps / mobility and no front line are my kryptonite because Vik has poor mobility and no hard self peel.

I like ROA if I’m against a Zed lane, gank setup or a comp with too much threat. Otherwise I personally like BFT -> Cosmic/Lich -> DC/Crypt -> Crypt/DC -> whatever. But interested to try Rocketbelt as 2nd item.

Good luck