BABY SHOWER HELP!

I’m due in July and we planned on having our baby shower Sat may 26th so we had enough time to buy anything else that we needed before baby boy gets here. My sister has claimed the position of baby shower planner from the day I took the pregnancy test. She told me and my husband that we just needed to make a guest list and she would do the rest and tell us when and where to show up. She just called me and told me that I needed to plan it myself because she can’t do it anymore. Now my question is, how do you plan a baby shower? This is our first baby and first time we’ve ever been to a shower in general. What do we need-supplies, decorations, food, drinks, etc. literally any suggestions or tips for a good baby shower would be greatly appreciated because I’m really stressed now. Thanks in advance.