You've scheduled an interview for a Sales/Marketing position in a company that works in the IT Field. what do you do ?

I have no experience in that field, Try my best to learn

I come to the interview with some of my professional archives and talk about it

Again attitude is important 

Attitude is important and if willing to learn and work as team learn then set goals for short term and mid-term then I am sure the employee new can have better ideas and creativity, attain success

If you are passionate in work & have slef beleive then no work is difficuilt in the world. But condition is that you must be honest, hardworker & dedicated.

First of all, you should be honest with the interviewer and tell him/her that you didn't work in that kind of field before but you're willing to be trained and study the product or services to be marketed. Now, if you've already the knowledge of the product or services, then definitely you will know your target clients or consumer in the IT industry. Second, try to make a research of the company as well as their products and services that they are offering for you to have the knowledge how to market it in the IT industry. 

Since its a sales role, first get an idea of the company and its industry and typically what it sells like is it into software services, or do they have software products , what technology they focus etc...
Also while responding to questions try to align your thoughts to IT industry with a sales pitch ...
Also get an idea about the industry and the territory ( if you know) you are interviewed for.
Get an idea about how sales works in an IT industry as the challenges and lead time in IT industry is different from other industries.
How would you align with technical people while on sales and get few points about your technical knowledge.

IT company professionals usually habitual to work in very robust environment of course they will expect the same from every candidate hence, you should carry a mindset where you make sure that you don't fall on go get attitude anywhere during your interview.
IT companies always seek for candidates who carries some knowledge in IT although it is for sales and marketing hence, you should make sure that you keep yourself ready with some knowledge about IT sector.
To be more informative it always better to have some understanding about advance technologies in IT and what opportunities can be created in the market.

A person who have experience in saleing IT products and services, well known about the techno functional knowledge of the product, its implementations done earlier, other market competitors technologies in/out to impress the client, other areas which can inhance client performance issues, reliability, disaster and recovery business impact, quick services and support, easy of use etc.
Other technical person can join him on further progress in deals and contracts.