The Scout is one of the hardest classes to master. In the right hands he can be a death machine and be a key part of a team. The scout runs very fast. This coupled with his shotgun which can only do extreme damage at close range make a great team. His pistol can be used at longer ranges when needed. The Scout captures points twice as fast, this makes killing a secondary task, the job of the Scout is to be on the objective at all times. This coupled with a Pyro would make a great objective couple.
The scout is also one of the weakest classes, at 125 Health he is very vulnerable to any hits he may take, especially if he gets hit by a crit, it’s very risky to go out and capture points. Use of different routes to flank the enemy will make you more successful in taking out enemies and then eventually capturing points. The Scout also has some good secondary items that replace the pistol, e.g. Milk will heal you and anyone that hits the enemy when they are drenched with the Milk. Crit-a-Cola gives your weapons crits for a limited time to cause some extra damage, maybe to help take down a Heavy. Bonk will make you invinsible for a short amount of time, the draw backs are that you cannot shoot, capture points or pick up intelligence. This can be useful for getting past sentries and enemies. Maybe not so much for CTF as engineers usually put their sentries in the intelligence room and by the time your Bonk runs out it’s probably too late.
In conclusion, as the Scout your primary goal is to capture points, attack weaker classes that you can take advantage of with your speed and double jump e.g. snipers and catching engineers out in the open without the protection of their sentries. If attacking other classes, flanking is the best option.