One common mistake beginning gardeners make when sowing carrot seeds is planting them too deep.
The seed packages say something like “place the seeds in a furrow, cover with soil and press the soil down firmly”. This makes it sound like you have to dig a small trench and heap garden soil over the top.
Actually, carrot seeds only need a shallow depression about one-quarter of an inch deep or so.
Cover them with a small amount of loose garden soil. Mixing some sand with the soil you use for covering will help keep it from crusting over. Crusted soil will hurt seed germination. Finally press the soil down firmly enough so the seed has good contact with the soil particles.
A shallow furrow for carrot seeds should be no deeper than 1/4 to 1/2 inch deep.
Carrot seeds take anywhere from one to two weeks to sprout.
Bob