So i need help what do yall recomend me i will be having next month my new born but i also have a…

So i need help what do yall recomend me i will be having next month my new born but i also have a girl and shes 1 year and 6 months & im not sure should i buy a car seat by it self or buy a double stroller for both girls & just the car seat by it self or by car seat and strollee together & besides that another stroller for my 1 year old ?