Roadside trouble falls into two kinds. Some of it you can handle yourself with the tools and the spare already in the car. Some of it needs a tow and a shop, and no amount of confidence changes that. Decide your split now, while you are sitting in the driveway, because the edge of a busy road is a poor place to start deciding.
Start with safety
Before any task, get the car out of the traffic lane if you can, switch on the hazard lights, and stay clear of moving vehicles. On a highway or a bend with poor sight lines, the safest choice is usually to call for help rather than work at the wheel. This is general safety guidance, not a substitute for local rules or for the advice of a roadside service.
Jobs many drivers can do
Changing a flat with a sound spare and the factory tools is a task many people manage with practice. Check, before you need it, that the spare is inflated, that the jack and wheel wrench are in the car, and that you know where the lug nuts and jack points are. Practise once in a driveway, not on a verge.
Refilling a low tire, replacing a fuse, or swapping in a bulb you already have are small jobs to settle in advance too.
Jobs to hand to someone else
Any fault whose cause you cannot see, any smell of fuel, any smoke, any warning light that stays on, and any tire that has been driven on flat should go to a shop or a tow. Continuing to drive after a sensible check is a reason to stop.
Check the contract for roadside terms
Roadside help is often a separate line in a contract or a separate membership, and its terms can differ from the vehicle coverage in the same form. Ask whether towing and roadside service are included, whether they carry a distance or mileage limit, whether you call a number or go through a shop, and whether you pay first and claim back later. Get the answers in writing. The contract is the document that decides what you actually receive.
To see how different companies lay out those terms side by side, start with vehicle service contract companies compared, term by term.