To find it definitively, you'll need to:
1. Consult your owner's manual: This is the best resource for your specific S10.
2. Use a repair manual specific to your year and engine: These manuals have diagrams showing the starter's location.
3. Search online: Use a search engine like Google, Bing, or DuckDuckGo with "starter location Chevy S10 [year] [engine size]" (Replace "[year]" and "[engine size]" with your truck's information). Look for images and videos.
Be careful when attempting to locate the starter yourself, as you'll be working near hot engine parts and potentially exposed wires. If you are not comfortable doing this yourself, take your truck to a mechanic.