Whats this from

Cannabis plant! No diary, no context..........impossible to answer with certainty. Could be one of many things or a combination of many. but without knowing what you may or may not be doing............ Best guess.......magnesium deficiency.

Heat stress/ Light stress will make the edges of the leaves stand up

Hey there don’t worry I know what’s going on When plants are small their leaves are very sensitive if you over water just a little bit and the soil sits wet for awhile the early leaves will do this also overdoing lighting or to much wind directly on seedlings can cause similar problems I would say it’s over watering thou the leaves being soggy and those brown crisp spots are all signs of over watering. Make sure to let soil get really dry between watering during veg

It looks like light stress or environmental stress to me. The sharp discoloration and crispy edges often happen when leaves are exposed to too much direct light, heat, or sudden changes in environment. If you haven't already, you could try raising the light a bit, lowering intensity, or checking temps/VPD to reduce stress.