Keep in mind (that) I'm a beginner.
断っておくけど僕は初心者だよ
keep in one's uncle's leading strings [in a leading strings to one's uncle]
おじに厳しくしつけられている
keep in [out of] sight
ずっと見える［見えない］所にいる
keep [remain, stay] in the background
表に出ない
keep in touch by phone
電話で連絡を取り合う
keep [stay] in touch with ...
…と連絡を取りあう
keep in tune with the changes
変化に合わせていく
keep inordinate hours
不規則な生活を送る
keep it handy
それを手元においておく
Keep it quiet. ＝Keep quiet about it.
それは秘密にしておけ
