I have hypermode, and well.... only hypermode. I don't have the credits to buy a pokéradar, can I still chain without it? And are there any guides on how to pile up credits so I can buy the radar soon?
Nope, you need a PokéRadar to start a chain, the HM only powers it.
Task list, the market, and interacting way too much could be a good way to earn credits. I'm currently earning Credits by selling items I don't need on the Market, or reselling items I see that are offered way too cheaply. You could also try buying a PokéRadar in the trade forums with a different currency (GP, ZC) instead of earning the credits.