I'm a beginner too, but I had these exact same questions too.
My first brew was a lager kit and it came with kettle finings. I used those and it came out crystal clear, no secondary.
Second brew was another kit but with no finings. Wife was away so I stuck the fermenter in the fridge for 2 days before bottling, and added 1tsp of gelatin (mixed in with some water) at the same time. Came out crystal clear, no secondary.
Brew #3 was an all-grain batch, used Irish Moss in the kettle. This one I did rack to secondary but only because I wanted to harvest the yeast and save some cash on the next brew. Wife was back so the fridge isn't an option this time, so I crash cooled it in a plastic container swapping out 2 litre ice containers twice a day. Came out crystal clear.
Brew #4 didn't use a secondary, just 3 weeks in primary. Also used Irish moss in the kettle. I'm bottling tomorrow so it's currently crash-cooling in the plastic container with ice bottles, already I can tell it's going to be crystal clear.
So my advice is to crash-cool in a large plastic container if you don't have the fridge setup. Really fill it up so that the water line is level with the beer line, use lots of ice. Watch some youtube vids on how to fine with Gelatin although I suspect I would have got clear beer without it. Sure a fridge gives better temp control, I'm not convinced how important this is for crash cooling so long as you can get it down to more-or-less fridge temperatures.
The conclusion I came to with regard to secondaries is that I'll do it if there is a good reason to do so, but otherwise just use primary and I don't see that it makes much difference to clarity.