both
Titan history:
Founding Titan/Progenitor Titan (holds the "Coordinate" ability): Long history of Eldian kings - 145th King of Eldia (Fritz, the guy who built the walls) - Long history of hidden 'true' kings inherit this Titan - Uri Reiss - Freida Reiss - Grisha Yeager - Eren Yaeger
Attack Titan/Attacking Titan/Shingeki no Kyojin/Rogue Titan: Unknown past history of Eldian Shifters - Eren Kruger - Grisha Yeager - Eren Yeager
So yes, Eren has the abilities and memories of two different Titans: Founding Titan and Attack Titan. He also has the hardening ability gained from the bottle found with Rod Reiss' stuff.
Eren now has the "Attack Titan" power or the "Founder/original Titan" power??
Or Both??
Getting confused here.