At the start, you must know 2 non-damaging move, a STAB move, and a move of your choice. (STAB, non-STAB, damaging or non-damaging). Of the two damaging moves, only one may have a BP of 50 or higher. It doesn't matter if it's the STAB or the non-STAB.
By map tiles, I mean open the ingame map, wherever it is in your game, and count the number of tiles that comprise that route. I'm going by the way the town map works in gen III, where the map pointer is moved by the D-pad in a granular fashion. Each movement of the D-pad is a map tile. For example, in FireRed, Route 1 is 2 tiles long, Route 2 is 3 tiles, Route 3 is 4 tiles, Route 4 is 6 tiles. If the map in your game doesn't work that way let me know, and I'll think of something else. I may just list long and short routes for you, if it comes to that.