Lines
Move the mouse over a card and drag from one of the dots to another card. In the Format panel you choose the kind of line, arrowheads, dashed, or whether the line goes around other cards. Double-click a line for a label.
Mind map
Select a card and press the Tab key for a child; after that Enter makes a sibling. They are in the menu of the card too, as Add child and Add sibling. Lines and positions follow by themselves, and Tidy mind map arranges it. Does a card already have arrows to other cards? Then Convert to mind map turns it into a mind map in one go.
Arranging
A Section puts a frame around cards: drag the frame and everything in it goes along. Select several cards for Align and Equal spacing.