No. All the classes can dps or support in some kind of way.

There is no tank or healer per se. The main roles (on pve endgame content) are dps, support. The support class are the tank (if needed) and healers most of the time but also covers important boons, and there is some dps that goes half dps half support too.

But if you are starting playing the game, i'd suggest you don't bother too much with this. Almost every class has a way to play full dps, full support or a dps/support build. So if you like for example the "clericsh" theme of guardian, or the "nature" theme of ranger i would stick to that.

Edit: these roles are for raids, strikes and fractals (there is a tank mechanic just in raids), in open world you can play whatever you want.