Many guide books and all phrase books have a brief but workable explanation of how to pronounce and a collection of useful expressions for tourists. I prefer Berlitz.
Don't worry about perfection. The worse your accent, the more successful you will be because almost everybody you deal with will speak English better than you speak French and the whole point of your starting every conversation in fractured French is to show you don't have an attitude and then to get the French to switch to English, which they are more than happy to do, although I don't if it is because they are being helpful or feeling superior.
As it happens, I can't carry on a conversation French, but I pronounce it nearly perfectly. This has several times caused me to get into arguments with, as I recall, cops, waiters, and hotel desk clerks who insist that I do speak French when I tell them I don't. And then there was border security who questioned my having an American Passport because "Americans can't speak French, but you do."
The French say that to the extent I have an accent, its German. The Germans say I have a French accent.
Its helpful to memorize a few phrases like:
There is a reservation for (your name).
Learn how to say please and thank you in French and do it a lot.
Do you have a table for x people? This is more efficient than saying We would like a table for x people because Do you have in French is a simple "Avez-vous"
The most essential sentence: Avez-vous un WC (or toilett)? (where is the rest room?) note the connotation of this expression. It assumes 1] they have a rest room and 2] you can use it. This makes it harder for them to say no.
Should they not switch into English after you stumble through a French sentence or two, your options to change to English are to say 1] Je nais comprende pas Francaise (I don't understand French. For the reasons described above, I prefer this to 2] Je nais parl pas Francaise (I don't speak French) or 3] Parley vous Anglaise? (do you speak English?), or 4] just start talking in English.