The term "will do" in English normally implies future action. If that is the intent, you can say "Yo haré alguna cosa", or perhaps "Voy a hacer alguna cosa". This can also imply present action, for example "Will you help me?" does not mean "at some time in the future I want you to help me", but rather "I want you to help me" or "Can you help me?". If this phrase is the answer to such a question, it would then be "Puedo hacer cualquier cosa".
Cualquier cosa
Para mí lo que sea = Anything (will do) for me.¿Qué hay /(hay) algo para mí? = (Is there) anything for me?Remember and be careful:MÍ--- me / IMI --- my
Cualquier cosa
no me puedes dicer nada
No quería nada.
si necesitas algo
Yo no digo nada personal
Haré lo que sea / fuere
it is Voy a hacer lo que quieras
preguntar nada bebé u
puedes hablar conmigo sobre todo.
"Ellos no van a ver nada"