Broadly what idrive said.
History of albion trucking Co. Left working in a freightforwarding office (had been a van and an flt driver before), meant I had contacts there. Shortly after got in with a new start plastic trunking company. That was great because I had OK paying load going out and loads coming back for freight forwarders. Got in with a very niche blue chip, just did an ad hoc load one day, they came back, did more. Moved into 7.5s as well. Couple years later contract for all their work from the Northern office. Acquired more customers in the same niche, then got contract for the whole of the UK, moved into 44 ton as well. Retired after 28 years
My advice is do what you feel will work for you. If you can get work to start with, doesn’t have to be amazing needs to pay enough and get your foot in other doors. Vans are cheaper as a way to start, but as idrive said, the competition is brutal.