I think you're definitely on the right track here. Your process looks well thought out, and you have a good understanding of how to adapt what you want to translate. My answer here is largely suggestion, so feel free to compare it to the work you've done and see what you think fits best.

Faal Jun los aaki; zu'u fent ni bahlok. Rok bolaav praali ko faad hofkah; Rok aaki wah votahrodiis okaaz; Rok vokrii dii sil; Rok kinboki zeim vennesevahzen amative ok moro. Orin nu ol zu'u wundun fin lumnaar se vokunsedinok, zu'u fen faas ni vokul; fah Hin qalos los het; Hin tuz ahrk hin du'ul drun dremi. Hi wahlaan hofkah fah sili ko suleyksejun se paali; Hi bolaav hin moro wah frul sleni; kogaani bo unslaad; Vahzah, zu’u fent siiv kul ahrk aaz pah sulleselaasi; ahrk zu’u fent praan ko hin Hofkahsejun mahfaeraak.

“The King is my guide; I shall not hunger; He grants my seat in warm halls; He is my guide to un-treacherous seas; He restores my soul; He is my leader through winds of truth towards his glory. Even now as I travel the valley of the shadow of death, I will fear no evil; for Your presence is here. Your blade and your crown bring my peace. You raise a hall for my soul in the realm of my foes; You grant your glory to my ephemeral flesh; my blessings flow ceaselessly; Truly, I shall find good and mercy all the days of my life; and I shall rest in your Palace (in the Hall of the Lord/King) forever.”

The shepherd-sheep metaphor can’t be preserved in the dragon language, so in my adaptation I approached it from a king-servant angle; instead of leading us to green pastures, He’s giving us a seat in a warm hall.

There are a lot of different ways to translate the biblical “Lord” (this word alone could warrant a discussion thread), and I think all of them have some degree of viability. Thur definitely works—it implies God’s rule is right by nature, that there is nothing over Him. I opted to use jun to further strengthen the king-servant angle. It also takes advantage of the other meaning of jun as a “guiding light,” since this passage is more about how God guides the narrator in particular, and not about his lordship over other things (where thur might fit better).

Another thing I did in the adaptation was mix formal and conversational grammar—all references to God (You/Your/His) use an explicit pronoun, while references to the narrator (my) use the possessive suffix -i. What this does is elevate God as the subject, but also illustrates the relationship between God and the narrator in a personal light, that the narrator would use this kind of personal grammar when talking to God.

With all that subjective stuff out of the way, here are a few tips to help you out with the dragon language, specifically:

• Unlike English “I”, zu’u isn’t always capitalized in transliterations.
• Articles like fin and aan are often cut. In my translation, the only article that’s used is faal, the formal “the”.
• Not necessarily something that’s incorrect, but using more compound words can help lend you more of the dragon language’s style. For example, you could say sulleselaasi instead of sul do laasi for “days of my life.” You don’t want to overuse this, but compound words in the right places can lend more weight and importance to a passage you want to highlight.

Your attempt shows rather a good grasp of draconic. Some points:

1) The definite article 'fin' is exceedingly rare. When in doubt, drop it.
2) zu'u capitalizes exactly like any other non-name word.
3) Here 'want' has an obsolete denotation 'be lacking' which laan does not share. Cancel out the negatives instead.
4) Long chains of ... do ... do ... usually become compounds ... do ...se...
5) Kaal connotes subservience to the protected. Vahlok 'guardian' has a similar but weaker connotation and thus fits the monotheistic God somewhat better.

For comparison, here is how I might do the translation (still sentence for sentence). Punctuation preserved.

Faal Thur los dii vahlok, zu'u piraak pah lanaan. Rok ofan praani nau graag pindaar: rok aak zu'u wah brit rath. Rok mul sili: rok aak ko vensekul naal ok moro. Ond, fod zu'u rovaan vul lumnaarsedinok, zu'u faas nid vokul: fah zu'u ahst hi, zahkriil ahrk mulaagiil dii spaan. Hi wahl kipraan fah zu'u us dii hokoron, hi nonvul klovi voth revakiil; kogaani los unslaad. Vahzah tol kul ahrk aaz fen grind pah suli, ahrk zu'u fen praan ko hofkahsethur mahfaeraak.

Thank you, both Paarthurnax and Frinmulaar.I greatly appreciate your insights and assistance. I really like how Paarthurnax perseved the meaning in the passage, through his use of changing the context to the that of Skyrim instead of the sheaperd context that is within the Bible. I also, like how it flows when translated back into english. very poetic. 

Kogaan

Ps. thank you for all advice and assistance helping me grow in the language.