So I used some of my DM XP to make a level 5 (tier 2) Arcana Cleric for some tier 2 content in the coming weeks. My main has gone out of tier 2 and I wanted a change of pace from my Bardlock, Barbarian, EK, and Druid (have a lvl 4 life cleric that's awesome too) and figured the Arcana would fit the bill. Any suggestions current Arcana clerics may have for an Arcana NoOb? As far as build, I went with half elf since you can't be Aasimar and go Arcana and for the extra skills. At 5 he currently is 10str/14dex/16con/10int/16wis/10char with taking resilient at 4 in con. The 2 wizard spells I took were fire bolt and prestidigitation for some ranged ability and who wouldn't want prestidigitation and thaumaturgy on the same character. I know 17 is a long way away for a tertiary character, but with the DM XP I will be soaking up running tier 3 and later this year tier 4, I have a lot to dump on some character. Seems like having a guy that can cast Wish once a day for the 25k worth of diamonds for free then true resurrection the next day on whomever he likes is pretty damn awesome.

I know this isn't optimized, but should be decent, fun, and versitile. I just want to avoid any real pitfalls people may have seen playing Arcana. Thanks in advance!

You already get the Arcana skill from the cleric subclass - there's no need of it from the half-elf.  Do take Perception, Religion and Insight as skills, as they tend to come up in play as well.

The only thing I'd suggest is swapping out Firebolt. Fire resistance/immunity is common and it doesn't have any useful side effects.

Chill Touch is a safe bet since the only things that resist both necrotic and radiant are celestials, and it can completely shut down regeneration and healing. Some monsters have no condition that can shut down their regeneration, and others like vampires can still recover HP through bites even if you shut their regeneration off with radiant damage.

Alternatively, Shocking Grasp gives you a useful move to block counterspells or opportunity attacks, either against you or someone squishier like the wizard. If someone in the party likes knocking enemies prone, you can get advantage against downed opponents.

If you're a big fan of Guiding Bolt or Inflict Wounds, True Strike will help make sure you don't waste that spell slot.

I thought about chill touch but as I have sacred flame for the radiant, I wanted to go with something that had a different damage type. Without heavy armor, I don't feel like I will be totally front line, but a close second.

You'll be very unlikely to be relying on firebolt, in my personal opinion.  With firebolt, that's a ranged attack roll, meaning that you'll be needing to avoid people getting Cover while they're in melee with your party, and you''ll suffer Disadvantage to use it while in melee range yourself. Far easier to fall back on Sacred Flame, which calls for a save instead of an attack roll, and avoids all those complications.  

There's no real reason to get a non-Radiant damage cantrip for the sake of swapping out damage, since the chances of you having to fight aasimar or celestial critter (the only monsters with radiant resistances) are generally vanishingly small. Even in the cases where you do encounter such opponents, you can always fall back on Magic Missile or the like for damage. Now, I originally assumed you wanted firebolt for the 120 range on it.  That's not a terrible thing to consider, but its also very game dependent - lots of encounters happen inside buildings, caves and forests as often as they do open plains.  I personally find the extra range to be unnecessary on average, but your game might be different and it might be a concern there. But if you absolutely want a second damage cantrip, definitely focus on utility rather than just damage type.  Is the range of firebolt necessary? Having issue with an opponent healer or regeneration? Chill touch has your back. Shocking Grasp robs opponents of reactions, which can be very useful in a lot of cases. 

Sacred Flame is your main, now think in terms of what you'd like to see else done. 

Absolutely, sacred flame will be the go to for the most part. The range and other damage is a bonus and I don't remember ever seeing many enemies that heal themselves in any encounter even through tier 3 with my mains at 14 and 12. Chill touch would be really good if more things heal for sure.