What software to make blueprint plans?

[OM2]

Can anyone recommend some software to make 'things'.

Something that helps create plans in 3d and helps work out measurements.

Easy to use without training would be good
I've heard of CAD software. Never used - all I know is that everyone says there's a steep learning curve.

Free open source would be great.
Online only would be good as well.

Thanks.

 

[Tigercubrider]

Look at SketchUp

 

[OM2]

@Tigercubrider looked up on mobile.
Looks good. Will try on laptop later.
Web for personal is free. That's great.