Please can any one tell me. How i can claim on going over my capital gains for the first time on selling shares

Or pay an accountant to work it out for you!

Could anyone please give brief explanation of the 28/30 day rule on CGT when selling then re buying the same shares with in the 28/30 days

hi
yes
if you sell a share then unless you wait 30 days before buying it back (in whatever quantity) then you are not allowed to use the 'new' purchase price for your tax calculations
similarly in reverse if you seeking to establish a loss

if yu want to hold without waiting then buy back in your wife/girlfriend/son/daughter name
in which case you should 'squeeze' your broker as you selling and buying same quantity so spread should be marginal