Help with my garden!?

i have to questions about my garden. firstly, i was at a store today and they have a plant there. the people at the store dont know what the plant is. i think it looks like a grape plant but cant be certian. it has kind of a stiff dark green stem, with 2 other tiny little separte things at the bottom. its not to big.. maybe 5 or 6"? is it a grape vine? and secondly my strawberries have gone wrong and i dont know why. can i have some tips with taking care of them? and thirdly (i know i said it was only 2 questions) can you tell me how to take care of tomatoes, chillis and eggplant? i have a small little space of land and it dosent have very good nutrients. what kind of soil and mulch should i use? thanks a lot!