There are online guidebooks for most countries, often with forums where you can chat to and go paddle with new people. Facebook is also a heck of a thing, with thousands of groups to get used kit and find people to paddle with. Another good thing to try is just turning up to a kayaking festival and chatting to people, or the classic method of just finding a canoe club and signing up!
1.(as long as it's not whitewater) Go where you want to paddle and just do it! You will probably run into people there, and/or other kayakers or wannabe paddlers might decide they really want to join you someday because you're having fun and exploring or ?
2. Join a local paddling club and/or Facebook group or use Meetup ... None around? Then start one 🙂
3. Ask the more active paddling employees at the stores that sell them in your area.
4. Maybe meet and perhaps go paddling with people selling or buying a kayak on Craigslist (aside from that minority who are giving up th sport or never really got into it). I have occasionally met cool people to paddle with when selling a used kayak.
5. Run around an extremely busy intersection during a red light with PFD (life vest), dry suit, and full face helmet on and wave around the biggest paddle you can find and yell as loudly and much as you can 😉 ...