It's a fallacy that breastfed babies don't get enough iron. In fact, the iron in breastmilk is more easily absorbed than the iron in formula, so BF babies don't need the massive doses of it. If you are healthy, then your milk will contain sufficient iron for your baby. It USED to be a concern, which is why cereals tended to be recommended as a first food, because they have extra iron added. However, if your baby is eating some solids having iron (cereals, meats) by around 9 months or so, this is usually plenty of iron for his needs.
For the first year, solids are mostly for practice and exposure and less for nutrition. This gradually changes as you approach and pass a year (there's no magic age when suddenly solids are more important or anything!). Breastmilk remains the primary source of nutrition for at least the year. Offer the breatmilk first and solids after, and you probably won't go wrong. Have you checked out the information on Baby Led Weaning? It's and awesome method for introducing solids!
Some babies never use a sippy cup and go straight to a straight cup. I personally started around 6 or 7 months offering one (with water) at meals - so when I offered solids, I also offered the water. My kids mostly played with it at first, but gradually got the hang of it.
HTH and have fun with it all!