Can the Search Engines help people Worldwide to find my website?
Yes. If your Website has been listed by some or all of the Search Engines, then your site should appear in an appropriate listing when someone types in a relevant keyword or phrase that matches data on your site. The only problem is where your website appears on the list - near the front or at the end.
If its near the front, there's a good chance your site will be found. If its near the end, then it probably won't. If your site has been optimised as much as possible for most of the major Search Engines, then there's a pretty good chance that you will appear to the front of the list, hopefully in the top 50 or 100 sites.
Incidentally, Search Engines are very fickle. One day you could be in the Top-10, and the next day not even appear in the Top-100.