Sea Otter Classic with kids and a travel trailer

Hi all, I am hoping to stop by the Sea Otter Classic on my way back from a camping trip on Sunday, April 13th. I will be in a truck pulling a 20ft travel trailer. I have a couple of questions (I have never attended):

1. I have a 5, 3, and a 1.5 year old. My 5 and 3 year old are very into mountain biking. We try to go once each weekend. Both can ride but usually my 5 year old is shredding and my 3 year old is on a KRS (kids ride shotgun) on my bike. I see that there are kid-friendly activities on the website https://www.seaotterclassic.com/kids-stuff/ . For people whose kids have participated in these activities, did your kids have a lot of fun? Are there other things not listed on the site that my kids might enjoy doing? (eg, watching some of the adult racing – not sure how accessible this is)

2. I'm wondering what my options are for day parking? From reading the website, it sounds like I am unable to use the day parking lots and I'm not sure about campground availability but it would be great not to need to unhook my trailer.

Thanks in advance for any responses