Try asking couples that you personally know, and have been married a long time. They might have some tips and tricks that they learned from their years of experience of marriage. However, you have to learn how to discern the good tips from the bad, and be objective about it. Go through freely available marriage resources in your library or even on youtube.
The best way to get meaningful advice about your relationship is to ask the people closest to the two of you that really know each of you for help. Your closest friends know you the best. Or, if you’re closest friends aren’t friends to both of you together, bring one friend in for each of you but get an outside perspective from people who do know you. Or another option is to see a couples counselor or to both talk to people that you completely trust. The way to do this to get the most meaningful advice no matter what the scenario though is to be completely open and honest when seeking the help.
Marriage advice abounds and can come in the form of online forums such as this one, or even a relative who has been happily married for a long time. In fact, almost everyone will want to give you their two cents on marriage, based on their experience. Just be objective on the type of advice you receive and discern for yourself if it is workable and feasible for your marriage.