よろしくおねがいします！ is a very useful expression in Japanese that shows respect for the other person and expect their relationship improves from now on. However, there isn’t a specific translation in English, and the exact expression seems to change depending on the situation.
Eg: 1. 『はじめまして。よろしくおねがいします。』→Nice to meet you. (Situation: When you meet someone for the first time.)
2.『こんごともよろしくおねがいします。』①Casual context: with a friend. →”Let’s keep in touch.” ② Business context: with a coworker, client, etc.→”I’m looking forward to work with you.”
There are much more uses and meanings for this expression, but keep in mind that context and situation are the clue to understand it.