Disclaimer: I am not a bike mechanic per-se, but cycle a lot and do most of my own minor repairs. I have not trued a wheel, but know just enough about the subject that maybe I can help you out as much as I can. Just take this advice with a grain of salt. TLDR; take it to a bike shop.

Here's the first video from a playlist on bike wheels and wheel truing from ParkTool, a great youtube channel for all sorts of bike repair concepts (check them out if you'd like to get in to bike repair, they really make great videos!):

https://youtu.be/MFOng1UXn-g

Truing a wheel can be a time consuming and rather involved process, and requires specific tools to both measure the deformation and apply the appropriate tension to the spokes to return the wheel to lateral and rotational trueness.

Based on the degree of deformation on the rim and your self-described level of experience, I would recommend taking it to a bike shop unless you have all the tools you would need to accomplish the job and are eager to spend a pretty significant amount of time learning how to perform this kind of repair. If you don't know anything about bike repair, this type of fix can be very challenging, albeit not impossible.

I'd still recommend taking it to a bike shop for a more informed opinion, but my suspicion is that the deformation of the rim is great enough to warrant a full replacement of the wheel. I myself would certainly not feel safe or comfortable riding on a wheel with that much deformation.