First Time Burning DVDS

I would like to burn some DVDs files from this two formats .MKV, .AVI

Since I have never done this task before and Its seem I bought the wrong blanc DVD's (4.38GB) too.

Task 1 - I Have to cute size some of my full DVDS rip (7.16GB) by using 123DVD Platinum v8.0.7.3 But I am not witch files riped form original DVDS needed to take out.

Task 2 - I am not sure what free software to use to burn this DVD to my friends, one of them use X box console.

I have read many software but in the end as I read reviews the don't support these two code-cs.
I bought this software for the purposes to Rip and Burn DVDS.

I haven't use AVI2DVD, because I am not sure what format I need to transfer to rip and burn to a DVD

and since DVDs only support 438GB..........
thank you for all you support and help on my behalf