I am afraid this is an the impossible question, You can get to #1 position within hours of posting a page but others you will never make the top 100.
It all depends on what your trying to rank for. Lets say for example your keyword is BMW, I think it you would struggle to overtake the brand and reach top slot.
The page below from this site is in #1 position only after a 2 or 3 days but the phrase is not very competitive so was a lot easier to rank well and quickly.
You can however go for what is termed low hanging fruit, long tail phrases, these tend to be far less competitive and easier to rank for.