To give you what weapon to attach to each character:
Byleth (Normal Outfit, both genders) - Ridill
Byleth (Enlightened One, both genders) - Creator Sword and Aegis Shield
Jeralt - Lance of Zoltan and mounted to a horse
Edelgard - Aymr and her shield
Dimitri - Areadbhar
Claude - Failnaught
Hubert - just a dark tome design
Ferdinand - Lance of Zoltan, a shield and mounted to a horse.
Linhardt - any white magic tome
Caspar - Axe of Zoltan.
Bernadetta - The Inexhaustible
Dorothea - any black magic tome
Petra - Sword of Zoltan
Dedue - Axe of Zoltan, a shield and mounted to a horse.
Felix - Sword of Moralta
Ashe - Bow of Zoltan
Sylvain - Lance of Ruin, a shield and mounted to a horse.
Mercedes - Ichor Scroll
Annette - Crusher
Ingrid - Luin and mounted to a Pegasus.
Hilda - Freikugel
Lorenz - Axe of Ukonvasara and mounted to a horse.
Ignatz - Bow of Zoltan
Raphael - Axe of Zoltan
Marianne - Blutgang
Lysithea - tome
Leonie - Bow of Zoltan
Yuri - Sword of Zoltan
Balthus - Vajra-Mushti
Constance - Scroll of Talos and mounted to a pegasus.
Hapi - Hrotti