Newbie - bonds

I have been doing some watching and reading.

What does the yield history mean with open close etc ..? Ie WIA030 says 3.8% at the moment.
The coupon rate is 4.25%.
Put in $100, each year I get 4.25%.
Matures in 2023, 7yrs away. I get $4.25 each year of the 7yrs.
It is trading at $103.609 so I am paying a premium for it for the a $100 value so need to account for that I know.

Is the yield percentage the adjusted return with the premium price at the time? Ie that $103 over the $100.

Also how do I know if the bond is a fixed rate or a floating? Such thing as a floating?

The stated yield is the "yield to maturity" (I think). It's related to discount rates and the time-value of money. The theory behind it basically says that money received today is worth more than money received in the future. The yield is the discount rate that leads to the price being equal to the present value of the cash flows.

If you don't understand / want to learn more, I suggest googling "present value" and "bond pricing"

I'm currently a third-year Finance student so this is based off what I've learnt, may be different in the 'real world'.