Help! Burnt ends I think

Can anybody tell me what’s wrong with these?

some information on your grow might help, like what medium, what nutrients etc.......

How’s your ventilation, Does adequate airflow exchange through your grow. Because if it looks like yellow spots it could be a case of leaf septoria. It’s a fungus caused by an adequate airflow and can go from yellow to black to your plant being dead if you don’t address it quickly. Remove all the fumhis
Infected foliage but It is not completely Necessary to remove the affected leaf entirely. Also be sure to sanitize with plants removed from area thoroughly.

I hadn’t been the best caregiver to my plants since I started them. I didn’t have a fan constantly blowing in the room in the beginning but the last two weeks I have had the fan on all day and night. I was using a small amount of blood meal since I couldn’t get bat guano. I think I may have had the light closer to the plants than I should have. There are gnats all in the soil as well. Are there any tips on how to remove them? Iv read about putting sand on the bottom of the drip tray and on top of the soil.

Remove all the affected leaves, Go to the plant section of your nearest Meijer or Walmart and look for something called Three and 1 or 4 & 1 spray something it’s like five bucks that’ll address the fungus, mites, bugs. And maybe invest into a box fan they’re like 15 bucks. Even a five dollar one would do the job. Also disinfect the entire floor, their containers, and their lights but be careful and not do the bulbs while lit also by removing everything from the area that isn’t attached. There’s some more shit you can do but I know it sounds like a lot if you want to keep them. Taking care of girls isn’t as easy as a lot of people think. But you should see some recovery.

This is my third grow but the first two I just assisted. It most definitely is not easy as I thought. I removed all affected leaves this morning and I’ll disinfect today as well as look for the spray. I couldn’t find anything at Walmart yesterday so maybe I should try Lowe’s? I do have a box fan and it has been blowing directly on them on the lowest setting. I hope this works. Thank you!