en_tn_lite_do_not_use/2ch/32/05.md

Hezekiah took courage and built up ... He built ... He also ... he made

The readers should understand that Hezekiah probably commanded other people to do the actual work. Alternate translation: "Hezekiah took courage and commanded the people to build up ... They built ... They also ... they made" (See: rc://en/ta/man/translate/figs-synecdoche)

Hezekiah took courage and built up

Possible meanings are 1) Hezekiah strengthened his position by commanding the people to repair the walls of the city. You can make this clear by using the connecting word "by." Alternate translation: "Hezekiah strengthened the city by building up" or 2) he became encouraged. Alternate translation: "Hezekiah became encouraged and built up" (See: rc://en/ta/man/translate/writing-connectingwords)

the Millo

This is a part of the wall on the north side of Jerusalem.