Technically, your question is outside the purview of this forum; however I think answers to your question could be helpful. I’ll assume you are working in the USA.
Pay rate: As a general rule most contractors/consultants charge 3X the industry standard pay rate for the job being done.
The reasons (logic) are:
Your tax rate on these earned monies goes up. When you work for a corporation you’re actually splitting parts of the tax bill with your employer – they pay some and your pay what you see on your pay check. Your effective tax rate should be about 40 – 60% more than is you work in a corporate environment. The good news is that you can write off expenses if you’re a LLC or declare your self as a proprietor. So, your taxable rate is equal to revenue(income) – cost of doing business(expenses) = net. Net is what you pay taxes on.
The first year you can file your taxes on your earnings normally (April 15), however the second year and beyond you will be required to pay taxes quarterly.
Depending on what state you live in, I recommend you take between 40 - 50% of your net income and save for federal taxes plus a percentage for state taxes if you have it. In my state (Georgia) I keep 5% for state taxes. If you don’t plan and save your taxes it will be painful come tax time.
Insurance: Contractor insurance? I don’t know you need to ask your client/customer what their requirements are while on site. Yes, you need to increase your rate to reflect this cost item or bill your customer/client for this.
For personal medical insurance – this is where you will get an education on what’s wrong with our medical system – expensive and insurance and medical companies are sneaky!! I recommend you buy major medical coverage so you’re not financially destroyed by the medical industry if you break a toe or equivalent. Just pay for office visits out of your pocket.
If I think of anything else I’ll post here…