Unknown insects. Need help!

Quick and effective solution, you will never have problems in your grow again: Step 1. 1 liter of water + 20g diatomaceous earth + potassium soap until it starts to bubble, it's better to mix with lukewarm water for a more homogeneous mixture. Let it cool and spray the plant, the underside of the leaves is very important, don't forget it. Always do this right after turning on the lights and move the light away until those leaves dry. Repeat in 48 hours if there's a lot of pests. Step 2. Sprinkle 1 teaspoon of diatomaceous earth on top of the substrate, focusing on the plant's stem. You can check your crops and see how effective it is.

There are many solutions to get rid of them, but frankly this early on I would just start from the beginning, make sure to clean the space and any equipment to get rid of all, use new soil that you're sure has none and get on with a problem free grow.

Looks like Root Aphids. Root aphids are tiny insects that feed on plant roots. About 1 mm long and ranging in color from yellow to green to brownish-orange, root aphids are often confused with fungus gnats as some adults will grow wings. Now in order to fix this I recommend you treat your plants with neem oil or a pyrethrum-based spray, which will need to be used early during the infestation. You may also water a Spinosad-based insecticide into the soil, or utilize Beauveria, a fungus that contains spores that will attack the root aphids.

Hey! It happens to me sometimes too! Put up a sticky trap to catch the adults, then the larvae move when it's dry, so try to wait to water until 1-2cm of soil is dry (after you've transplanted it) treating the soil also with an organic spray (even homemade). I usually use a mix of garlic, chili, and neem. Sprayed on the soil, it kills them pretty much instantly ahahah