“appropriate for one to eat and drink.” Many verses in Ecclesiastes encourage people to rejoice and have fun in life (cp. Ecc. 2:24-25; 3:4, 12-13, 22; 5:18-19; 8:15; 9:7-9; 10:19; 11:7-8). See commentary on Ecclesiastes 2:24.
“see good.” This phrase is idiomatic, and it is hard to understand exactly what the idiom means in this context. Generally, “seeing” something is experiencing it, and thus it can mean to “experience good” (Seow, Anchor Yale Bible), or it can have the meaning of “find enjoyment” or “enjoy good” (R. Belcher Jr, Ecclesiastes; Mentor Commentary). Or “see good” can mean to “prosper.” Or, the idiom can mean all of these things, which is why the idiom might have been used in the first place. By leaving the idiom in the text, the reader is presented with all these meanings.