Homebrewing - Beer, Mead, Wine, Cider

I've never tried my own home brew before and I've been sitting on two kits for years now (got them sitting the pandemic but never found the time) and I wanted to try to start something

The original juice and hops are probably toast by now so I'll have to purchase some new, but I've got two of those jugs and the other bits that come with them.

I also have a small orchard in my back yard and wanted to try to use the thousands of plums in get every year to make some kind of lambic ale.

Any advice is appreciated!