If your primary objective at this stage is to determine the viability of a retracement strategy of your making, then don't confuse the objective with targets and stops and contracts and so on. Otherwise, if things don't work out at a satisfactory level, you may dump the whole thing when the strategy may be perfectly sound yet the tactics leave something to be desired. Determine first whether or not the retracement strategy, i.e., entries, meets your objectives.
You may, however, while you're testing retracements, gather data on how far price typically travels after you've entered your trade, what the recoil typically is, how long it takes for price to get moving. IF your RET entries are successful to whatever level you've chosen as acceptable, you will then arrive quicker at a set of hypotheses regarding targets and stops and whether those stops should be fixed or trailing or, if fixed, if and when they should be moved.