Are they parasites or stress? Help

Looks like that long yellowing leaf you circled is not part of your cannabis plant, but more likely a random weed or grass that sprouted in the pot. It’s not a parasite and doesn’t look like it's causing stress to your main plant, but it should be removed so it doesn’t compete for nutrients or water. The cannabis plants themselves look healthy overall, with no obvious signs of insect damage or nutrient issues. The leaves are a nice green, and the structure looks solid. I also noticed you’re using yellow sticky traps, which is great for monitoring pests like fungus gnats or whiteflies, and it looks like they’re pretty clean so far. Just make sure to keep an eye on the undersides of your leaves every few days for any bugs or eggs, and let your pots dry out a bit between waterings to avoid root issues. Overall, you're on track, just pull that unwanted plant and keep doing what you’re doing.