I agree with the others...your pictures are spot on and descriptions are clear. I would say time will draw the sales as well as promoting the hell out of your shop through etsy, facebook, etc. There's lots of free ways to advertise. I'm an artist and I've had more results through local galleries and other online sites than etsy, but maybe my 2 cents is worth something :)
You sold 4 items already and in only 3 weeks after opening your shop. I guess I reached 4 orders after 2 or 3 months after. I liked your items, don't forget there are tons of other shops and sometimes it is just hard to be reached by any customer.
It's a lovely shop. My main advice is to have more stock. Have a good range for people to select from. And think of events like baby showers - have a good stock of a particular type e.g. boy baby shower invitations.
Also, what helps is if in your listing you link back to your store or a sub-set of it. E.g. Link to "MORE BABY SHOWER INVITATIONS", to keep people in your store rather than going back to the general Etsy search.
Edited to say - I know (I really do!) it takes time to build up stock - so try to work on your shop every day, even if you only manage half an hour. Those half hours build up!
Tania, it's nice to see an Italian seller :-) Your shop is beautiful, I see you are using all your tags, you have perfect pictures and your SEO seems fine to me. My only advice is to keep adding more!! I've favorited your shop, it's just too cute!!
Thanks for your advices, i will create more birthday cards and thanks cards Step by step i add new items. I try to add 2 or 3 item each week. I opened from 29 days