In the early stages of a book, make a list of the characters. Avoid having similar names unless it is for red herring purposes.
Introduce your characters gradually, not all in the first chapter.
Is your villain rotten to the bone, or does she pull weeds at the lake front on Saturday mornings, after reading to the fish?
Does every character need a name if their role small? If they open a door or seat you at a table in the restaurant, their task may be enough.
Avoid similar names, e.g. Ann and Anna, but consider using them if mistaken identity is your red herring.
Write a little every day. Don't start editing until you finish the first draft.