Let's gather the things you need to keep a parakeet.
Literal
Parakeet [object-を] keep [purpose-ために] necessary things [object-を] let's-gather.
インコ (parakeet) is in katakana as standard for animal names. 揃えましょう uses the volitional ~ましょう for 'let's (gather).' ~ために marks the purpose: in order to keep a bird. A practical, inviting instruction.