This is a fun first attempt at RTB. I think your first track is miles better than my first track. I butchered the pit lane blending onto the track portion of mine. You have some walls that arent snapping to the ground in areas where the terrain is changing elevation drastically.
The track has to sharp of an elevation change for GT3 cars in one areas where I come off the ground a little and then bottom out but that can be "track character" so don't take that as a serious flaw. My tracks sometimes do the same. RTB made tracks all feel very similar because the Xpacks pretty much offer the same stuff for everyone so it feels like Im playing one of my tracks and one of the many tracks I've played on here. I had fun and I hope you have fun playing it because that's what its all about. You can improve on this for months if you wanted or you can make some slight alterations and continue to have a ton of fun. Either way keep it up!
happy racing :)