If you are interested in a Marketing manager job then you should be well informed about what the position entails for you. Most Marketing managers have a lot of responsibility and can be in charge of a lot of different things at the same time.
For example, one of the typical activities for a Marketing manager is to take the sales data and statistical records from a company and use it to make Marketing decisions. For example, say the firm is wondering how they should spend their advertising dollars this year. They might present the manager with past sales data, advertising costs, and conversion rate data based on their research for how effective past campaigns have been, and ask the Marketing manager to make a decision about how they should best spend their ad dollars.
Or the company might approach the manager with a list of ideas for new product development. The firm could choose to pursue a handful of new products this year because they are retiring some old ones, so they need a decision made about which ones to pursue. The manager could take into account current trends, the economy, past sales data, and competitor sales data in order to try and determine which products are best to pursue and develop.
Because there is such a range of potential decisions to make and skills required, any Marketing manager is likely to need prior experience and lots of real world, on the job training if they are going to be up for the job.