people in French high schools learn at least one foreign language these days. So young people will speak probably either German, Italian, Spanish or English. You'll have better chances with trying to speak English to young people. Because the older folks will have forgotten what they learned at school if they don't use it regularly.
As Toulouse is quite close to the French-Spanish border, they will have a lot of Spanish lessons there.
But rich people from GB have been buying properties in southern france in the last couple of years. And Toulouse is also a tourist region. So hotel or camping site personnel, salespeople in central shops and waiters in city restaurants also probably speak at least some words English. Or they have at least one person in the place who does. So if you ask 'Parlez-vous Anglais?' (= Do you speak english, pronounced 'par-LEH vou ong-LAI') they can get someone who can help you.
Practise pronounciation when learning French. It's one of the most complicated things in the language, and the French tend to be confused about false pronouciation.
I have been on vacation to France a couple of times. I speak some French but my family doesn't. You usually get along fine in shops, supermarkets, restaurants and the like without much of the language.
If you feel insecure, buy a small language guide that you can carry in your pocket. You can read in it when you're queueing /reading the menu in a restaurant/ entering a shop. Then you just look up the words you want to use.
If you don't know how to pronounce 'Un eau mineral s'il vous plait.' and people don't get you, you can point at the phrase in your book and have them read it.
Also, carrying a phrasebook will show people that you're a foreigner. Makes them speak slower and more articulate.