MG Blitz Gundam
Brief story time: my first articulated "model kit" was the G-Frame Blitz Gundam. I was amazed at the simplicity and aesthetic for <10 USD, and it inspired me to get into the hobby.
Late last year I got the MG Blitz Gundam, and it is everything I liked about the G-Frame times 20.
@wizardbeard All I did was panel line with homemade acrylic panel line washes (it is not recommended to use oil or laquer washes on ABS, of which this kit has a lot). Of the ~50 kits I have built, I've only put a matte top coat on 7 of them.
My first MG kit was a Z'Gok, and I probably put together almost 20 HG's and 30MM's before it because of your same mindset. My recommendation is to just start simple. You can usually make edits later, but if you never open the box you'll never build the kit
To add on to this, as long as you don't make any physical changes like etching new lines or drilling new holes, you can always walk anything you do back. Obviously if you do a full paint job that might take a while strip off, but it's still fully reversible. So build it, and then as you get more practice you can come back and do your additions.