Cynthia - First of all, congratulations on building a successful business it must be so exciting to have interest from distributors. Answers to your questions:
1. A distributor agreement is a binding contract between both parties so it's best to have a lawyer review it, but it is not a necessity. In fact, you could do this just via email if you choose to. The question is how well that agreement will stand up in court if there is a dispute, so I'd rather have something like this be well crafted.
2. Are they stocking distributors or are you fulfilling the orders they take? Huge difference in the risk, obviously. If they are not stocking, they are really just sales agents and the agreement will be much simpler. I have a sales agent agreement I could share with you, but it's oriented to repping cloud services so I'm not sure it would fit.
Send me an email at [removed to protect privacy] if you'd like a copy of the sales agent agreement. UPDATE: I'm new here and didn't realize I couldn't leave an email. Send me a message via Founder Dating if you'd like to take a look at the sales agent agreement I mentioned.
And good luck!