Im new to the game, HELP PLEASE

hey guys
ive go my plant in my window, its in plain old compost and i just giv it water whenever the soil seems dry, other than that it just gets the sun.
she is about 3-4 weeks old and about 14 cm high. however the bottom leaves are starting to get brown patches/spots on them, what does this mean, is it natural or am i doing something wrong, or am i not doing something, ive posted some picture but its not the best. any help would be great!!

Looks ok but you need to start giving it nutrients that contain nitrogen so the leaves dont all turn yellow......imo

Nutrients and more light! If you cannot put it in the light for at least 6 hrs, you need artificial light. Chec out the FAQ section on this site and it will help you. Many questions can be answered there.

yeah give it half strength complete nutes