It all depends where you are going. If you are in central Tokyo, there is probably a 50% chance that they will have an English menu available. If not, they may have a photo menu or model food outside that you can point to. I'm sure the staff will do their best to explain it to you if you don't understand. Finding your way between stations isn't that challenging - the Metro stations and the JR all have English signage. The more challenging aspect is finding an exact location - such as a shop or restaurant. The block system (as opposed to the street number system) can be a challenge to get used to. If you can arrange for data roaming or a Japanese data SIM, you'll be able to use Google Maps or Four Square - which will make getting around much easier.