I admit I need help on who they will be electing to what exactly.
Tommy Robinson and Carl Benjamin are who you are pulling for.
the EU parliament is analogous to Congress (the EU council of ministers - with its spokeperson Donald Tusk is analogous to the Senate with veto powers and the EU commission (Junckers) is the US civil service.
The EU parliament has elections every 4 years and these guys are based on population - so the UK has 73 out of 570 odd MEPs
The elections will be for these 73 MEPs - last time around, in 2015, there were 8 UKIP MEPs elected - one of whom was Nigel Farage