After you imported you design to Avocode you can open it in Inspect mode. Here you can get all the required data - like measurements and code for the elements of your design. You can as well export all the assets you need.
Inspect mode consists of stage with your artboard and two sidebars - left and right.
In the left sidebar you'll see all the layers of your design file and all the necessary tools:
Hand - to navigate around
Select - to select elements
Measure - to get measurements
Colour - get colour information
Slice - to select specific area of the design
Pixel checker - to align the design with your coded app or website
In the right sidebar you'll find all the information from your design. If no element is selected you'll see information about the whole artboard like used colours and fonts.
Once you select an element you will be shown the layer(s) you, code and more.
See more to adjust all the outputs