Should I evolve this growlithe?
The growlithe is with 72 HP and 695 CP currently, it is above average and its best attribute is its HP, which is trending to the positive. I am at level 22, almostly level 23.
Answers
After getting new Pokemon:
1) Appraise it. Make sure you know your team phrases to get an idea of if it's any good or not. If you don't know what phrases to look for, Google "Pokemon go appraisal phrases" and find your team phrases.
2) If you find any mons worth looking into(checking IVs), use this site's IV calculator. It asks for Pokemon cp, hp, current dust cost to power up and whether or not you've powered it up or not yet(which you shouldn't have usually as you're supposed to check IVs first imo)
3) once you find the IVs and overall % rating, and it's one you're gonna keep, favorite it (this prevents you from accidentally transferring it) and try renaming it to it's IVs. For example if you have IVs of hp:15 att:14 def:12 and it's 87% overall, rename it "15/14/12 87"
Some players like to put abbreviations of the Pokemon's moveset too.
It's up to you.
What I do, I'm on Instinct. The phrase to look for for appraisals on Instinct is "can battle with the best of them" which is the first phrase of the appraisal. If I don't see that then I most likely transfer it unless it's rare Pokémon. The top appraisal phrase means the Pokemon is rated 82% to 100%. Players generally hang onto Pokemon that are rated 80%+.
Keep in mind that move set is hugely important too. So don't transfer all Pokemon just because it's maybe only 75% rating. I have a Gengar 51% that I kept because it got the best move set.
Take some time and go through all of your Pokemon and check each rating.
You might have some 100% perfect ones and not know it. Or worse, maybe you transferred a perfect one thinking it was bad.
It's weaker than I'd evolve these days (lv30) but there's no harm in evolving something that you're confident you'll get more of (and better). At your level evolve stuff but try not to invest candy and dust in powering up unless you get a really good Pokemon - you'll start to get find better Pokemon as you go up the levels when that candy and stardust will be more useful.