If you are going to set a strat up for slide, the first thing you do is block of the tremolo if it's a strat with a tremolo. Essentially, a flat fretboard with a hard tail is ideal, especially if you have to tune to an open tuning and back to standard. If you string it with 11's or 12's (the set may come with a wound "G") get a 19 or 20 if possible, unwound "G".
Some people use open tunings, some use standard tuning...for starting out in open tuning, try open E. You can tune in open D and capo the second fret which gives you the same sound at a lessor tension (For an acoustic, it's a good idea) but then you have to work a little harder and since you are beginning, get use to Open E or open A and the patterns used in both, then when you use open D or G or even open C.
If you have any questions, feel free to send a message...sliding is what I do!