Spanish UK ISA Equivalent- How to invest in Spain?

I’ve been contributing to my ISA in the UK for years. Since considering a move to Spain, this is something I’m aware won’t be tax wise after the move.

Few Questions if anyone can help

1) does Spain have an ISA equivalent?

2) What’s the smartest ways to invest in Spain? (I’m aware this is a very broad Q and down individuals. For reference I invest in mutual funds through my ISA. I’d like to continue to do this)

3) Has anyone moved from UK to Spain. What did you do with your ISA?

4) Are there any good YouTube people who cover Expat investing in Spain? E.g. Dave Ramsey is a great resource for wealth creation in the USA

5) is there anything to be aware of that people miss when it comes to investing in Spain

Thank you for your time answering