My Little Cup Dilema

Ok so i made a rookie error and just boght a bag of multi purpose compost thinking it would do the job, my seeds have almost finished germinating now will this stuff be ok to put in little cups for the first planting? (ive seen people using little cups for abit not sure why this is!!) ive got bigger pots but ive noticed people usually start with a small container, how long untill i transfer to the larger container and will the multi purpose compost do for the little cup stage? sorry for being so clueless im sure the pro-growers get sick of shit like this !!

Did you buy "compost" or "potting soil". If it is just compost you need potting soil. Compost is for mixing in with soil. You should transfer from small cups to larger containers (at least 3 gal.) when they get to be about 4" tall. Just go ahead and repot to your final size container. If your plant is a little stretched you can just bury it a little deeper, won't hurt a thing. I always bury mine deeper.