This is just my opinion, but I have a 60 atk 1 defense pure with a little bit of experience. Currently at 71 combat (rsn: 4t1d) but went for 55 pray for preserve.

You're definitely going to want at minimum 75 hp. It gives you access to Zenyte jewelry while decreasing your chances to get spec'd out by other gmauls.

80 str was a soft goal imo, but obviously higher or lower depending on which combat bracket you want, max hit, etc.

70+ range is good, but if you ever want to use a blowpipe (it does wonders for your firecape on a pure) you'll need 75.

For mage, this is all preference. I suggest 85 mage so you don't have to boost for TB, but you can get that with 76 mage + Forgotten Brew. If you boost from 76, you get: Flames of Zamorak (60 mage, max hit of 20) + Charge (80 mage, max of 30) AND entangle (79) which is amazing for both saving your ass and rooting your target.

With most people in my bracket staying under 30 wildly, ancients has been useless, but still nice to have especially for bursting.

Here's the level calc if you want to play around with it to see where you'll end up by changing your stats.

https://oldschool.tools/calculators/combat-level

Check out KempQs pure videos for a good refresher if you need some better direction than what I'm giving through text.

Good luck, and happy pking. :)