Hi, Amalia, welcome to Upwork!
No, you don't need a contract template because on Upwork, clients set up the contracts and it's all built in to the platform.
Your question suggests you may not have reviewed the information for new freelancers. If not, I strongly encourage you to read all of it before submitting a proposal and absolutely before accepting an offer. If you browse this forum, you'll discover a substantial amount of the traffic is new freelancers who jump in without understanding how to use the platform and wind up losing time & money.
Upwork provides contracts. To ensure absolute clarity, I may send the client a formal proposal, since the description in the job post is often of little use. My standard format is
Our Understanding of the Current Situation
What we believe you need
What You Will Receive
Timing and Billing
I send this as an attachment to a message so that it is part of the Work Room.
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