Inherited IRA RMD

My dad passed away in Feb 2023 leaving me and my brother as beneficiaries of his Trad IRA (50/50 split).

His RMD for 2023 was ~$11,000.00 and he received IRA distributions in Jan and Feb reducing his 2023 RMD amount to ~$8000.00.

Question #1:  How much do I have to withdraw for the remainder of 2023?

Question #2:  I know about the 10-year rule and I am not an eligible designated beneficiary. How do i calculate RMDs going forward?  Is it based on my age or my dad's age?  

 

thanks