My suggestion. As you have seen, there are categories, and topics. Take some time to browse them first and find out where all the topics are posted. There is a search function in each section to search and see if someone has already started a conversation in the area you are interested in.
If you do not find the answer you are looking for then start a new topic. People on here are more than happy to help.
But by all means make sure you read the rules and regs for this site. The moderators are really good at their jobs and we all love this site because it is clean and family orientated, I for one want to keep it that way.
Good luck and I know you can find answerer's here.