Whilst exploring a new city for the first time can be fun, it is always good to have in mind at least a couple of places that can provide life’s essentials - food and rest. There is nothing to stop you from simply wandering around and letting your nose guide you to the best smelling cafe or restaurant. However, knowing that if you fail miserably, or can’t find anywhere within your budget, that you have researched via the internet, and found a Barcelona restaurant (for example) that others recommend can help to calm your stomach from making those embarrassing rumbling noises.
If you have not yet booked a room for your stay, then City Vacation’s page on Hostels and Hotels in Barcelona could well help you out, though I should point out that this city’s pages are currently a work in progress, with a full re-launch expected some time this Autumn. The restaurant page already has details of not only the style of establishments you can expect to find in Barcelona, but also specific recommendations for good places to eat.