Well, I did my first interview with Ricardo Bare from Arkane Studios in a language that was not my own so first of all: don’t be nervous, it will go ok.
Second, I’d advise, if possible, to exchange some messages with the interviewee before the thing itself. Kind of an out of the box an ice breaker. You’ll be able to check how responsive she/he is and get a general impression on what the tone or the focus of the interview should be. Kind of a “read the room first” type of situation.
If it’s your first one, I advise to send your questions beforehand, even if during the interview other stuff comes up and you deviate a bit from the original plans. Sending the questions beforehand helps also because it will make the interviewee more comfortable, will help to earn some trust and, if the questions are interesting or require to go in-depth you will be able to give the person some time to think, and that will translate in better/more interesting answers.
The “surprise factor” and holding back your questions only really makes sense for investigative journalism or if you are covering some kind of story and you need to stick to your guns, but if you are not doing that, being open will help a lot.
The most important advice tho is the one @sosadillatron already gave. Be honest, be sincere, earn the trust of the other person. This will go MILES towards she/he opening up to you and putting both of you rowing in the same direction.
Being nice, polite and earnest will be your greatest assets.