Looking for some help and advice

Hi, I come here looking for some advice and help . Over the past few months I have started getting to grips with blender and now looking to start doing some more stuff and thinking of creating a little animation , nothing fancy just trying to put the skills I have learnt so far to good use.

Im looking at having a very basic character sitting at chair in an office or somewhere like that then go from there to walking down the corridor then down stairs to outside where they will then walk down the street to there car.

Before I was just following tutorials and using images offline so there hasn’t really been much thought into the scale of the models I have previously been making. I would like to start having appropriate sizes for the models I would put into my scenes so that things dont look out of place or things looking to small or to big in comparison to each other so im looking for a bit of help and advice on how I would go about achieving this.
Another quire I have is how would it be best to transfer from one scene to the next ? Would I just be best to add the the parts to each scene on different layers and do it that way or is there any other way someone would recommend?.
Hope that all makes scene and thanks for any help.

Blender’s default unit is meter. Dimension values of the object is real world values. Example:

Dimension (1, 1, 1) = 1m, 1m, 1m.

If you scale an object to 0.5 then real world dimension is “1 * 0.5 = 0.5 m.” etc. etc.

Best transfer method is “File > Link”.