Incidentally, whilst I myself wear sandals at times in summer, I predominantly use them just to give my feet a break and for the late afternoon's after I've finished for the day. October/ November I would be tempted to carry a comfortable, well cushioned, lightweight pair of sneakers rather than sandals for the evening.
The vast majority of us wear some kind of trail runner on camino, a few prefer sandals or boots. We are also split on the subject of Gore-Tex versus non-goretex (I personally only wear Gore-Tex in the middle of winter, and that because of snow).
If you're planning to start in a couple of weeks I hope you've already got something, you ideally want to walk in new shoes for two or three days back to back (approximately 10 to 15 km) to ensure there are no manufacturing defects.
Should you still need to buy something remember that you need something that is at least a half-size larger. Most of us seem to go a full size up. Your feet will swell and splay as you walk, a wider shoe than normal is useful for many.
Yes there are guides on here for that as well, any half decent hiking shop should be able to assist you, simply tell them you're walking the Camino.
Don't hesitate to post your packing list on here, many do and somebody will chip in to assist.