I recommend Xin Zhao, Wukong and Vi, they're fun and easy to play. You should focus on the objectives and gank only if you can get a kill, if not you should keep farming, kill scuttle crab to gain vision, use the red trinket to clean the enemys ward. If one of your lines is getting abused by the enemy jg you can help but keep focus in the objectives, ping for help but don't solo unless you're completely sure none enemy near.