The manufacturers of Libre have been pushing it pretty hard. As a result, they have been running free trials. I did this and got one sensor (and another when it fell off) and a free reader/spare BG meter as well as a voucher for free P&P when I made my first order. For me this was arranged via my hospital but if, as in your case, the hospital is not great, I would recommend calling Freestyle and asking them for a trial. Don't tell them about the one you are getting from your friend.
This trial will give you a chance to find out whether you are going to get any value from the Libre before spending any money and whether you can actually cope with it being stuck in your arm: some people find it uncomfortable or find that it falls of or just don't like it on display in the hotter weather.
Although your hospital are not great, I would also encourage you to push them for a DAFNE course. Experiences of these vary depending on how much you know already and how receptive you are to making a change to your diabetes management. But it should provide a kick start to carb counting.
It probably all feels to much at the moment but once it becomes habit, it will just be like cleaning your teeth - assuming you clean your teeth twice a day. Good luck.