No, you don’t have to do that.
An ISA is a tax efficient “wrapper” around some investments, which means that you don’t pay tax on any gains when you sell shares in future. Generally speaking, it’s a very good thing. In the other account type (called a Basic account by Freetrade I think, but often called a General Investment Account by other stockbrokers), you may need to pay capital gains tax on the gain when you sell shares in future.
There are a few types of ISA (Freetrade’s is a stocks and shares ISA) and a bunch of rules about ISAs. https://www.gov.uk/individual-savings-accounts/how-isas-work
Only thing I would say is that if
- you have already contributed to a stock and shares ISA (with someone who isn’t Freetrade) this tax year,
- or if you had plans to open a stock and shares ISA with someone who isn’t Freetrade before early April (and it doesn’t sound like you had plans like that),
then: don’t make any trades and get in touch with Freetrade support tomorrow This is because you’re only allowed to contribute to one of each kind of ISA in any one tax year.