So it seems I am foolish enough to sign up for the IWKA World Championship Karate Tournament (It is specific to Isshinryu). It is August 8th. Me being a executive class white belt at that. If I am going to actually be an executive, I would like to be Chief Information Security Officer - unless some other position pays better and has a better dental plan. I hear CEOs get better stock options, but have to do more boring meetings. I like security stuff, but I digress here. I am learning the kata I will be doing (Seisan), and I'm also learning the Karate rules way of sparring. I hope for the best, but will plan to give premium effort and have fun. Since I don't actually know that much Isshin-ryƫ Karate (or any Karate) yet, I don't expect any miracles. I will say this, I think the Karate Club I am learning Isshinryu from are top notch, despite being free (I base this theory on other Martial arts schools I have attended/currently attend). Entirely likely what I end up doing is some sort of Muay Thai/Kung Fu/Kali Hybrid with 5% Isshinryu added in. Not sure what will happen, but I can promise you I will see some Karate during the event, and that is good.
FWIW, the people I know who compete in kumite prepare for tourneys by practicing with folks from other clubs. I understand it's helpful. You might try talking to your sensei about hosting or visiting another dojo for kumite practice. Hope you win, bro!
Yes, sparring with other people from another dojo is a must. After sparring with people in your same dojo, you all know each other and how you each fight, etc.