Yes, there are many local events and meetups for electronics enthusiasts in the UK, including in the Brighton area. Here are a few resources to help you find events and groups:
Meetup.com - This website has many groups related to electronics and technology in the UK, including groups focused on Arduino, Raspberry Pi, and more.
Hackaday.io - This is an online community of hardware hackers, and they have a section on their website dedicated to events and meetups.
UK Amateur Radio Clubs - Amateur radio clubs often have events and meetings that are open to the public, and they can be a great resource for electronics enthusiasts.
University Electronics Societies - Many universities have electronics societies or clubs, which can be a great way to meet like-minded people and attend events.
Maker Faires - Maker Faires are events that celebrate creativity, invention, and DIY culture, and they often have a strong electronics and technology focus. While there hasn't been a Maker Faire in the UK since 2018, they may return in the future.
I hope this helps you find some local events and groups to attend!