Yes, you can also have a Cash ISA and a Lifetime ISA at the same time. A Lifetime ISA can only be used as the deposit to purchase your first home or fund retirement, and you can only save up to £4,000 each tax year into the account.
Having both a Lifetime ISA and Cash ISA can be a way to save more than £4,000 for your first home or retirement, or save towards other goals alongside your Lifetime ISA pot. You can also open more than one Cash ISA with different providers within the same tax year. However, you can only open one Lifetime ISA per tax year.
Just remember that across all your ISA accounts, you can only save up to £20,000 each tax year, and only up to £4,000 into a Lifetime ISA.
Tax treatment depends on individual circumstances and may be subject to change in the future. Must be 18-39 to open a LISA. Ineligible withdrawals may return less than paid in.