Yes it does seem that when you create a new menu item it goes to the bottom and there is no way to change that until you have saved it.
After saving the new item there are two ways to change the order.
If you are in the Menu Manager and have the menu opened so you can see a list of all the items on that menu, on the right hand side change the order to "Ordering ascending", then you can use the three vertical dots in front of each item to drag the menu item to the place where you want it to appear in the order.
The other way is to open the menu item itself. On the right hand side you can use both the "Parent item" and the "Ordering" to change the place that the item appears on your menu. Note that if you change the "Parent item" you will have to save it before changing the "Ordering". When you select an item in "Ordering" it will appear just after the item you select.