Train is one of the maps that have been updated early on so everyone is quite used to the new layout already. It is considered one of the most CT favoured sided maps.
A bombsite is usually harder to hold since there are more entrances to the bombsite than on B. This means that you usually have only 1 player on B and 1 player in connector, ready to assist where help is needed.
Due to most fights being taken at long range, it is totally normal to have 2 AWPs on the team.
Usually you will have three defenders on A, with one rotator in connector that helps you if needed.
Due to open sky-box, A bombsite is very prone to smoke executes. The executes are very common and you should save some of the utility when you see the smokes are flying in.
Some Terrorist teams like to rush outside without any utility thrown beforehand to catch you offguard, so you can throw an early molotov in front of Main.
There are three chokepoints on A – Main, Popdog and Ivy. You can choose many angles you want to cover each of them, so make sure you mix it up to not get prefired/molotoved/smoked out of your holding spot. There are different play-styles you can choose from. You can either play from far away and defend your spot from long distance, or can choose to be close.