I need help on when to say certain words like đưa,đem, and lấy. i know what each of them mean. can u give me an idea like when to use each word. And also give me a couple of sentences containing the 3 words.

Hi William,
It's nice that you come up with different questions on Vietnamese. Asking is a good way to learn.
To bring:
1."mang" or "đem" when there is no indirect object (usually people)
Eg. Anh có mang/đem một cây dù không? (Do you bring an umbrella?)
2. "mang cho" or "đem cho" when there is an indirect object (usually people)
Eg. Anh có mang/đem cho em một cây dù không? (Do you bring me an umbrella?)
To give: "đưa" (action of giving something to someone from you), "cho" (to give as a gift).
Eg. "Tim gives Phuong an umbrella":
- Tim đưa Phương một cây dù (Tim hands Phuong an umbrella )
- Tim cho Phương một cây dù (Tim presents Phuong an umbrella)
To get, to take: lấy
Eg. Phương lấy một cây dù từ Tim (Phuong gets an umbrella from Tim)
Tôi sẽ lấy cây bút màu xanh này (I'll take this blue pen).
Some collocations with "lấy": "lấy vợ/chồng" (to get married), "lấy mạng" (take away one's life)," lấy cắp"(to steal) ...
It may takes one day to talk about these verbs. Just basic ideas for you to understand.
Hope you're satisfied with our answer.
Nice day there!