Hello Arcanum!

I would recommend finding a nice and friendly (LS/FC) group to start learning tanking Amdapor Keep with. Your gear is fine for that, but I hear some DF groups can be rather...demanding. You should farm AK for the gear and tomestones and also maybe Castrum for DL tomestones. DL tank gear is very nice and you should start from getting that (body/head and legs/feet first). For weapon I'd recommend skipping Ifrit and going straight for Garuda, although you will need to kill Ifrit to get Garuda access.