Team-building

Newbie here just hitting the 2 weeks mark. Currently running MLF, Belsey, Merlin, Guinevere and Galahad in my team. Expecting to get the first mileage 5-star selector tomorrow to get Lueira. Only MLF is T1 while everyone else is T0.

Can I check after getting Lueira, how should I change my team composition? Other 5-star characters I have but not being used atm are Lisa, Lohengrin, Vivien, Tristan, Eva, Lancelot, Kay, Circe, Lua, Joan and Cristina.

Am getting a bit stuck at normal adventure Stage 29. Many thanks in advance! :)