Welcome to the forum. For the car you need to consider three things I think
First, is the car suitable for yopur everyday needs. For most towing is only a modest part of your driving so you need a car that is suitable for your everyday needs.
Second is the car heavy enough. The car needs to be heavy enough to control the caravan. To be aboslutely safe, the ideal ratio, if you follow the guidelines is that the caravan should weigh no more than 85% of the cars kerb weight. This figure would normally include 75kg for the driver so check if the manufacturer includes this in their published figures. This is advice and has been there for some time and might have been overtaken to some extent by improvements in cars and caravan handling, so going over by a bit should not be a problem. Before you buy the car it would be as well to get some idea of the caravan you want to see what weight you are looking at.
Thirdly there is the question of engine choice. Diesel engines do normally tow better and are more fuel efficient but there future is in some doubt so you do need to be careful with that one. Petrol engines do make good tow cars but look for ones with a better than average torque figure. Caravans provide a lot of wind resistance so the more power the better.
Do not be tempted to look at manufacturers towing limits where they are higher than the car other than to be sure that the car can handle the weight. These are based on the ability to restart on a 12% hill and are more a measure of the strength of the driveline than what can be towed safely on a motorway.
Hope this helps.