Using the forum is perfectly fine, there is a combination of input / questions from both newcomers and highly detailed discussion here.
You dont mention if you use the website or mobile app to add records. You might take a look at a couple of how to videos here https://www.inaturalist.org/pages/video+tutorials.
There is also a Getting Started link there if you prefer text and pictures to video.
Ti help with the location question, we would need to know which method you are using ´website or mobile app.
Searching by colour is one thing the site does not support, but using the Explore tool on the website, you can search to see all types of plants seen in your county. https://www.inaturalist.org/observations?place_id=1076&subview=table&view=species&iconic_taxa=Plantae
You dont have to add an ID when you try to add a record. If you don’t it goes in under’Unknown’, which stiill falls into the Needs ID group. If you can, you should try to add at least something though, like Plants, Birds , Insects etc as it helps direct your record to people interested in those areas to reciew.