תְּבָרֵךְ (tevareikh) is the piel imperfect 2nd person masculine singular form of בּרךְ (to bless, kneel), from berekh, meaning knee: You will bless.
כַּצִּנָּה רָצוֹן (katzinah ratzon) comes from צִנָּה, a shield (using the Kaf prefix with the definite article): as the shield and כַּצִּנָּ (favor). Together: as the shield of favor.
תַּעְטְרֶנּוּ (ta’terenu) is the qal imperfect 2nd person masculine singular of עָטַר (to crown) with a 3rd person masculine singular suffix: you will crown/surround him.