Can someone explain how to make these effects with images in Photoshop?

Hi, for most of them, I'd play with some blur, on a backlit image, with some funky curves adjustment layers, a gradient map adjusment layer, and a risograph treatment:  https://medium.com/@stefanhrlemann/how-to-create-noisy-risograph-style-gradients-and-textures-in-photoshop-in-3-ways-394d6012a93a

There's a million ways to do any of these. What they all have in common is that they are very far removed from any "original", so it would list a pretty long chain of operations.

In other words, you're asking how to give a complete explanation of Photoshop's functionality in one paragraph.

The best advice I can give is to start by visualizing what you want. In my own experience, reverse-engineering what others have done isn't very effective learning. Finding ways to achieve what you want is much more effective.

Depends on what the original images shows. Many ways. Fill marquees and fuzzy them. Adjust tones. Working with brushes. Maybe there is even a filter doing this in one go.