Translation help

Heilsa!
I am wondering if anyone could help translate the following phrases
for me?

1)  "In Rage I Rise to Rown Aright!"

2) "Better to never begin; once begun, better finish."

3) "Hail upon the Holy Hill (Háaskrhöf ?) of High Ashes,
hail the Wolf Realm,
Strength to those who stand within,
Victory to those with Will to stay.

Truth and Trust remain,
Joys pass away.

These are the words to the Nothingman."

I am at a very early stage of learning anything about ON. Most of
what I have learned are things that I remembered from the Eddas or
sagas.

Am I to understand that ON is very similar to modern Icelandic? What
grammatical differences are consistant between the two?