Hi, Congrats on your pregnancy!
In regards to the itching, to be sure as the other women mentioned, just check with your ob/midwife to ensure it's nothing serious, but at a rough guess I would say it's due to this being your first baby (especially if your a smaller person eg: size 8-10) your belly is just making room for little one, keep up with the oils/creams especially the bio oil, however you may also like to try a shower gel available from the chemist called dermaveen?(spelling) it is soap free & pH balanced with no alcohol in it, which can dry the skin out, it also has a main ingredient of oatmeal which is a great natural soother for the skin.
The swallon legs, again as the other women mentioned check it out to be sure, but it is quite common in pregnancy and generally harmless, although can be quite uncomfortable, it may be caused by fluid retention, or if you stand on your feet for long periods and can also be heat related. My first pregnancy(now pregnant with #4) I had the swollen ankles, but it was also through the middle of summer (QLD weather!!) try to keep your feet elevated above your heart when laying down, if they feel warm you can also get a cooling mist from the body shop, I found this helped.
As for the sleep...LOL well good luck with that one, try not to drink too much water in the couple of hours leading up to bedtime, maybe try a warm milo made with milk, I have heard some women like to have a bit of fun with hubby/partner to relax (also wears them out too no doubt).. who knows really as mentioend above, it's really natures way of getting you into routine for when little one arrives, but make the most of naps throughout the day where possible to ensure you are getting enough rest.
All the best smile