Legally you can jump into an SEP aircraft and go flying as long as you have a valid licence with medical and your SEP rating is in date. As already said, you need to have done 3 landings in the last 90 days before taking passengers (depending on when you flew in December you may just be in date for this). Also as mentioned there may be club rules that are stricter than this - and no matter what the rules say there is also the wisdom of jumping in by yourself if you are out of practice.
