In order to best serve you, your Realtor® needs to clearly know what you need and want. In order to properly instruct them as to your needs, you will have to spend some time sorting through those needs.
One way of looking at things might be "is this a negotiable, or non-negotiable, issue?" For instance, if you have active small children or animals that may dart out of an open door, needing a house on a quiet, low traffic street would probably be a non-negotiable issue. If you want a fenced back yard for these same busy little ones, you may accept a house with no fence providing the yard space was there and the price of the house left you with money to build the fence.
If you list the things you are looking for and what is, or is not, negotiable, you have a good starting point for a discussion with your Realtor®. During your first conversation, your Realtor® may come up with a few things that you have not thought of.
Between your original list and what comes up through your conversation, your Realtor® will have a good idea of the type of house to show you. This is just one more area in life where clear communication will make for smoother sailing!