Congratulations on Attaining Level 70 in Neverwinter!
This may be a bit overwhelming, but I hope this guide can help you navigate through all the changes in the game.
If you have not joined a Guild already, I highly recommend it. Guild membership has a great deal of benefits! They can assist you with plenty of things. The most notable to a level 70 is your Business Gear. This armor set is terrific for a new level 70. This is bought from the Guild Armory, using Guild Marks. You also help the guild get more boons when you contribute, so it is beneficial for everybody to do dailies from the Guild Stronghold. These include doing the quests supplied by the Builder, Ranger, along with the other NPCs, and running Heroic Encounters for Influence. These can be tricky, so don't be afraid to request support. 1 of these must go with the Artifact Set you select. I suggest reading class builds that will help you get the best set.
With these seals, you can Speak to the Seal Vendor at Protector's Enclave Seven Suns Coast Market and Buy some Ostorian Rings. The rest of the equipment in there's garbage, so don't be worried about it. You may even use extra seals to buy these rings and salvage them for AD once you've equipment up yourself. You could even place these earrings on your Companion if there's a Ring slot. You may request a guild member to craft them for you, or you may buy them quite cheaply on the Auction House.
You'll find a purple enchantment square in your new armor and weapon. These are special enchantment slots that need a particular type of enchantment. Something is better than nothing, so I suggest finding the cheapest enchantment available to begin. Read your course guides carefully to find out exactly what enchantments you should be saving up for.
I also highly suggest respeccing your personality when you reach Level 70. The expectations of your course at lower levels will be different in comparison to Level 70; for instance, a Devoted Cleric is expected to cure at lower levels, but they're expected to buff at Level 70 content. You get these Symbols by finishing zones and collecting the rewards from the effort window.
You may replace everything else on your character sheet when you hit Level 70, also. The Drowcraft Shirt and Pants are relatively cheap on the Auction House, or you could request a guild member if they could buy a few for you with Demonic Ichor.
If you have not found a guild however, the League Armor is available at the Auction House. This is bought with Astral Diamonds (AD). You'll require AD for different items, so I do not recommend this route unless you've got no other alternatives. You may get AD by performing Random Dungeons and Skirmishes daily.