Welcome.
I hate be dishearten anybody but the game you tread can be a hard start. I had a young lad start work for me a few years ago. He is a gent, lovely guy, hard worker, lots of contacts and in short was a fitter by trade and wanted to get into hire. I wasn't to fussed for hire but discussed used sales (its what we do) and he came on board with a view to do both. His contacts were from the rugby club where he played rugby as did his dad, friends, family and builders etc that knew him.
Its surprising how few times he asked if we could hire something out, perhaps he knew i would say no because all we seemed to get was the odd man wanting a digger for a weekend for £50, no insurance. Like i was going to send out a 6k asset for £50. I would rather sleep at night knowing its locked away and safe. All the contacts who said they would rent kind disapeered or the ones that did show interest were used to paying peanuts (civils etc) Then they get damaged, lost, stolen, buckets go walkies. Invoice delays and all that. Perhaps i am just making excuses because i just dont like the idea of it. I could also be totally wrong and maybe he had a lot more enquirers than i remember or maybe he just never asked.
With reference to buying and selling, there are zero auctions you can actively buy at and make enough to make a living, yes you can make a bit but believe you me. You can go to auction, look at 500 machines, earmark 10. For whatever reason they make way to much and you end up putting your arm up for something that looks cheap that you never paid attention too, then it turns up shagged. I am not saying its impossible but to actually make a go of it you need to buy differently. Buying from end users etc also isn't cheap but you can generally find they are honest so you know what your getting. The issue is its surprisingly difficult. I personally would think ringing people up trying to buy kit would be a doddle. Its not. Then you are liable for warranty's, comebacks, profit and loss, insurance, market changes and you need a good bit of stock to keep the flow right. A lot of people have also tried the middle man route (i did when i started) but I reckon everybody copied me that market is flooded too. I found again to make a living you had to invest in your own product.
What i have found and the only words of advise i can really give is that your people you would of thought would help you out, dont. Because they have existing relationships, sell direct and all that. Yes you will get a few but its not enough to pay yourself and trade.
enjoy.
Edit, also, i probably didn't explain auctions that well.. Its where most dealers send there crap. Including me. Its defo a eyes open affair,