How does the aids virus affect us in the beginning of the disease?

You may not notice. Most people, after recovering from primary infection (acute retroviral syndrome), have no symptoms for at least a few years. However, they are not normal. Their t-helper cell counts are usually declining, and they have higher levels of immune acttivation and inflammation. Most people have fairly advanced disease by the time symptoms appear, though there are a few conditions that can occur earlier.
Very variable. Aids disease progression is extremely variable in individuals ranging from rapid progression to death in a year to a decade or more of asymptomatic infection. This variability appears to be affected by other comorbidities, genetics, virus strain, etc.