"Tactically what do you do (remember this is all new to me)? Creep up a little more (within 4BW) and then charge in the next turn if not already contacted by the enemy in their turn."
If you start outside 4BW, so can't contact in this activity phase, and want to charge as soon as possible, I think the only consideration you have is what the British will do in their phase.
One option they will have is a retrograde move backwards (1BW in line, 2BW in attack column). You obviously want to end your move close enough to the British that you can still charge them next turn even if they retrograde. Otherwise, the distance you end from them is not that important - you just want to make sure the flanks of your unit are not exposed or you don't end in the firezone of a 2nd British unit.
I am interested that the scenario you describe implies it is as likely the British will charge you in their phase. This suggests you are both fairly equal units. Charging one on one is unlikely to succeed (you need to double them to win) unless something is in your favour (you have 2 units attacking 1, he has multiple discs, you are better espirit with a better general).
There is no reason you have to charge. You could also change formation to line in your activity phase and move 1BW into shooting range. Then get into a musketry firefight with the British. Hope you put some DISCs on the British to allow you to charge in a turn or two witha better chance. Of course, if he has a better skirmish value than you, that might not be a good idea.
Cam