This is classical tapered headtube, 1"1/2 by 1"1/8
I buy cheap ones on aliexpress( you may find it on this forum ), but you can find plenty of branded ones easily too.
For the axle, they usually provide one, but it is generally heavy( not sure about ICAN, but some builder provider lighter ones now ).
The one I really like is the DT Swiss RWS 142x12 ( with nut, as from the pictures, the drop outs do not appear threaded ).