Newbie

First question with a caravan - what are you going to tow it with?
Next, think about how many it will need to accommodate - yourself only, partner, children, grandchildren. That will give you an idea of the size and you can start to think about the layout that will suit.
In general with caravan you will need to use sites, most of which will have facilities like showers and toilets you can use. On pitch facilities will vary from electricity only to water supply and drainage but worst case you would have to go to a tap to fill up or drain to empty water. A camper / motorhome would give you more flexibility with places to stay and there are a lot of motorhome parking facilities opening up around the country with fewer facilities than campsites but much cheaper.
Prices of caravans will vary depending on age, size and condition and if you read some previous threads you can learn a lot from the experience of others. As a general rule of thumb the year of a caravan will give you an estimate of price: 2005 €5K, 2010 €10K etc. This is just a ballpark to give you an idea what you might get for your budget.