What Sentence or use of preposition is correct what should I say
You are on the point of a good start
Or
You are at the right point of a good start
What Sentence or use of preposition is correct what should I say
You are on the point of a good start
Or
You are at the right point of a good start
When you are at something, that something is typically a place - whether:
a physical area that one travels to
or a logical idea of "place" referring to "where" one is during some progressive activity like a project or race.
Point can be a synonym for place in both situations, though point would infer a narrower area than a place.
When you are on something, you are typically touching it and usually physically above it. (Of couse, on and at like many English prepositions have multiple meanings and appear in phrasal verbs.)
So this obivously can be true of many types of physical places.
I am at First Street. (First Street is a place)
I am on First Street. (You're physically standing on First Street)
Not so much with "logical" places:
I am at a good stopping point with this project and can take a break.
I am on a good stopping point with this project and can take a break.
To me the second sentence sounds a bit awkward though it's not completely unclear.
On point is also a well-known phrase meaning "well prepared" or "excellently done" so the use of on and point could be potentially confusing.
[countable] a particular time or stage of development The climber was at/on the point of death when they found him.
From Oald, point, no. 6 http://www.oxfordlearnersdictionaries.com/definition/english/point_1?q=point