core/strenght training/barre/etc for beginners

[calendria]

what would you recommend for beginners. EXTREME beginners.

I have always been, by physical strenght, weaker than most women so I am having a hard time finding a core training workout or strenght training etc that I can finish and go back for more, other than classical stretch. or choose your level pilates.

any ideas here? exhale is too hard for me. even exhale body sculpt WAY too hard.