Lie is about the relationship of the long axis of the baby as compared to the long axis of the mother. Ninety some percent of the time the lie is longitudinal, that is the baby's spine is parallel to the mother's--cephalic or breech are longitudinal lies. In a transverse lie, the baby's spine is at right angles to the mother's; in other words, the baby is crosswise in mom's uterus. Although during the pregnancy a baby may be in this position during a check up, they almost always move to a longitudinal position before labor starts. A baby in a transverse lie cannot deliver vaginally.
Attitude has to do with how flexed the baby is. Usually in a cephalic presentation, the baby's head is flexed foreward onto her chest and the spine is flexed into a C curve. This position works best. Sometimes the baby has his head straight up, like a soldier at attention. This is called a Military Attitude and presents bigger diameters of the baby's head to the pelvis. Often, during labor, the baby's head does flex foreward and progress speeds up. Showing even less flexion, sometimes the baby looks up and the brow presents first, this is even less desirable than a military attitude. Tipping the head even farther back, some babies come face first. On X-ray, the spine looks like a letter S instead of a C. Surprizingly, a face presentation is more likely to deliver than a brow presentation.
Presentation has to do with what part of the baby is closest to the cervix. A cephalic presentation is head first, a breech presentation is butt first, both longitudinal lies. A shoulder or hip presentation would be transverse lies.
Presenting part is presentation in more detail. A cephalic presentation can be vertex (head flexed foreward, occiput at the cervix), brow, or face. A breech presentation can be a frank breech, baby flexed at the hips with just the buttocks presenting, or complete breech, baby tailor-sitting with legs flexed at the hips, knees bent, or a footling breech with one or both feet coming to the cervix first.
Position has to do with the relationship of a marker on the baby to the maternal pelvis. The pelvis is divided side to side into anterior and posterior and front to back into left and right (mother's left or right, not the examiner's). In a vertex presentation, occipital bone is the marker.If the baby is Occiput Anterior (OA) the occiput is in the front right part of the mother's pelvis, so it is facing her back. If the occiput is in the back (OP), the baby is facing the mother's front. The baby usually doesn't come down straight OP or OA, but is turned slightly to one side or the other, giving you ROA, LOA, ROP, and LOP. If the head is facing mother's hip, it is Right Occiput Transverse ROT, or LOT.
The marker for a face presentation is the chin or Mentum. So you have RMA, LMA, MA, RMP, LMP, MP, RMT,LMT. A baby in one of the Mentum Anterior positions can deliver vaginally, but not if it's in one of the MP positions. (Picture a vertex delivery, as the occiput rotates under the symphis pubis you get extention of the head--it up from being flexed onto the chest. Now picture a baby coming face first, mentum anterior. The head is bent back as far as possible, looking out the vagina. As the chin rotates under the symphisis the head comes foreward. If the chin is posterior, the head is bent back as far as it will go and it cannot rotate under the symphis because it cannot bend anymore. Try being the baby and go thru the motions yourself to get a feel for the different movements. Lie on your back with your head bent as far back as it will go and imagine you're rotating under the symphis, then lie on your stomach in the same position and you'll see why you just can't rotate under it.)
Breech presentations use the sacrum as the marker. SA,RSA, LSA, etc.
Sorry this is so long, I hope I haven't confused you even more. Just look at the diagrams and imagaine yourself in the different positions. There is a book Human Labor and Birth by Oxhorn and Foote that has very good diagrams of all the positions, presentations, lies, etc. Your school library probably has a copy of it. Good luck.