Gearing progression for a new RDM 70

(I am not very sure where this sort of question would be more properly posted, so I am taking a gamble for here. Apologies if this is the wrong forum!)

I just recently reached my first 70, as RDM, just barely a day or two ago.

Looking around, I tried to find any sort of guide on how to properly progress with my gear, however either the guides were meant for pre 4.2 changes, or explaining how to deal with the new gear. It's left me unsure, and confused with how I should begin this climb.

Is there any tips, guides, or just general info that anyone can share that could help point me towards the correct direction?

Well i would think that while the Ala Mhigan gear is a good start. You could most likely run City Of Rabanastre for ilv 330 Gear and you also get a coin which in part could go towards upgrading the previous Tome Gear (Lost Allagan)
Your very first level 70 dungeons will also drop gear of course but that is only ilv300
Also i do believe you could turn in creation tomes for Lost Allagan, this would be a good start

Yeah the best start is going for the Lost Allagan gear using Creation tomestones. The previous Verity gear (ala Mhigan) can only be obtained with Centurio Seals now so they are only really good for glamour. Once you start collecting Mendacity you can buy the next set of gear, Ryumaku.

Yes, save up your creation and mendacity tomes through whatever means you prefer. Lvl70 Roulette requires at least i300 to unlock Skalla, and then you'll need to beat that dungeon as well as Ala Mhigo, Kugane Castle, and Temple of the Fist. At i310, you can run both the newer dungeons to unlock Expert Roulette. These roulettes will probably be your primary means of snagging tomes. Don't forget, creation tomes have no weekly cap, and you can hold up to 2000 of those at a time before you need to start using them up. Mendacity, however, is limited to 450 a week, but you can still carry up to 2000 of them. Once you hit an average of i325, I'd recommend trying out the normal version of Sigmascape too, as you can get part drops you can exchange for i350 gear. You can roll as much on a part as you want, but only until you win something from that fight. You can only win one thing per fight each week, barring the minion in the last fight I believe. The normal fights are actually not too bad once you've beat them and know what to expect. It may take some time to get what you want, but you might still find it worthwhile, and when 4.3 gets here I imagine they'll drop the weekly restrictions on these.

Eureka's still a thing for the moment, so if you feel like grinding the fate train you can upgrade the i290 job gear you get from the lvl70 job quest up to i350 (i355 for the weapon, same as the Byakko Ex drop but with more materia slots to boot!). Plus the boss monsters there will also drop mendacity tomes when they die (if your elemental level isn't too low for that fight, that is), which gives you an alternative to that. Once you have an average ilvl of 340, you're also open to try Sigmascape Savage if you're up for a challenge and want to upgrade your gear even further. Of course, that's entirely up to you since by the time you reach that ilvl all other content is pretty easy to get through.

Another note: You may want to consider looking into which secondary stats work best for your job. As I recall, RDM favors a balance of critical and direct hit, and below that on the priority is some determination and spell speed. If you don't plan on doing challenge content, it's probably not super important, but still something you may want to think about when deciding which pieces of gear to collect. For the most part, though, higher level gear means a higher primary stat, which is the main thing to focus on since that will be what your damage will mostly come from. If you're really interested in stat weights, you could try looking up the Balance Discord group. As I understand it, it's comprised of people well-versed in different jobs, and can offer advice on that subject. Choose what approach suits you best, and good luck!