Let's take a look at some newborn behavior and signs and symptoms of problems.
Is lots of crying normal?
Unfortunately for your ears but fortunately for your baby's health, the answer is usually yes. Newborns can cry lots and lots and lots. IF your baby has been checked out by a pediatrician and has no other symptoms, lots of crying is usually perfectly normal. Indeed, a baby's cry may seem angry, bored, or simply habitual.
Do pay special attention to any cry that sounds different than normal, appears to be the result of pain, or just worries you. These things are always a reason to get your baby checked out by your pediatrician. (Reassuring new parents is a big part of their job, so don't worry about bothering them!) Oh. Some parents go crazy when they hear their baby cry inconsolably all day long, and seem powerless to do anything about it. Do go to your own doctor if you feel like you're going insane and want to do silly stuff like shake your little one until the noise stops, or jump from a roof.
Some babies nurse for hours on end and seemingly never get enough. Other babies only breastfeed for a few minutes at a time and then go do other things, like sleeping or smiling at you. Some babies nurse while sleeping. Some babies get very distracted at the breast and let go, to look at something or to smile at you, all the time (this usually begins around the four-months mark). Guess what? All of this is normal. Formula-feeding parents have to stick to the manufacturer's or the pediatrician's instructions about amounts and schedules, but breastfeeding moms and babies can simply go with the flow excuse the pun and do whatever works for them, as long as the baby is healthy and gaining weight.
Baby hates solid foods?
Have you tried to feed your little one solid foods, only to find that he or she simply spits the food out and doesn't seem to enjoy the experience at all? If your experiment took place before your baby was six months old, they were probably simply not ready for solids. The World Health Organization recommends starting solids at six months, when babies are developmentally ready for their first solid foods. Even after that time, solids will not immediately become your baby's main food source. At the beginning, your baby will simply be engaging in a "Solids 101", trying some, rejecting others, and learning to get on with non-milk foods. In time, your baby will definitely move away from a milk-based diet :).
Not hitting milestones on time
Yeah, there are general guidelines about when your baby should smile, roll over, sit up, develop a pincher grip, crawl, walk, and start talking. No, not every baby will hit those milestones exactly at the "designated" times. That's normal. Some babies will be early, while others will be late. That's normal, but delayed developmental milestones can be a sign of something more. This is why you have to work in partnership with your doctor, regularly informing them of what your baby is and is not doing. Your expertise on your particular child coupled with your pediatrician's general medical expertise will give the most complete picture of what's happening, and whether or not you need to look into your baby's development in greater detail.
Many parents are extremely concerned about their baby's bowel movements, so it's important to mention poop here. All newborns have sticky, tar-like bowel movements called meconium at first. This is very difficult to clean up, but meconium will be a thing of the past after the first few days of your baby's life. After that, formula-fed babies will have fairly predictable bowel movements that take place once or several times a day. The consistency should not be firmer than peanut butter, or your baby might be dealing with constipation. Warn your pediatrician in that case. The color of formula-fed baby poop can vary. After a month or two, your baby may have bowel movements less frequently. Breastfed babies may have bowel movements every day, every other day, multiple times a day, or not for several days. The poop is more watery, more like mustard than peanut butter. You can read more about baby bowel movements here: Is your infant's poop normal?