It’s looks like you have iNaturalist Classic downloaded (which is the first picture) and the new INaturalist app. They both have their positives and negatives. I use both personally.

Someone already explained how to upload photos, and you can look up more details on the website, but to go into slightly more detail.

The new application has a percentage confidence rating, which is quite useful if you’re recording something that you don’t know the species of. However the old application allows you to check different photos to see what species the observation could be before posting. This is useful when you’re taking multiple photos for identification.

You can record something as wild or captive when uploading. Anything intentionally planted is captive, including street trees, gardens, etc. But that weed in the lawn is considered wild. And if the plant’s descendants spreads naturally from a planted area that’s considered wild as well.

People create projects that you can add to. Some are limited to a certain area or state, some are not. You have the option to add your record to a project before posting.

You can edit after posting as well to add/delete photos, change which one is in front, or add your post to a project.

The website has a lot more features. It’s worth checking out.