With all due respect to Encounter, there are better things you can do in 3 days in LA , although it might be worth stopping by for a drink before heading back to the UK.

To the OP, first, welcome to FT!

Second, I'd recommend doing a search on this forum (search upper right corner) or just pull up threads from the last several months (lower left, switch it from last 10 days to last several months & then click on show threads. A quick perusal of thread titles will show threads of people who had similar questions & which we provided info in those threads. That should give you a lot of info on possible things to do/see, and if you have additional questions you can then post those.

Third, provide a bit more info re: yourself/dad, what types of things you're interested in, budget range for hotel, if you'll have a car (necessary in LA), etc.

Enjoy your upcoming trip. Cheers.