Advice on LLCs and DBA

Hello. In 2024 I opened an LLC (before I knew much about LLCs or DBAs) to encompass both of my businesses. I make things with glass but I also intended on doing freelance graphic design. I was told by my lawyer friend the name of my llc didn’t matter and I really only needed LLC, so I created a super generic name I didn’t really care for on a whim.

Fast forward to 2025, I open another LLC for my graphic design work under the name that I came up with that I want my brand to be. Mostly because I didn’t want anyone else in my state to take it. I opened a bank account and credit card for my design business. Got an EIN.

Can I file a DBA under my second LLC and run business A (graphic design) and business b (glass stuff) all under the same LLC? With the same bank account and credit card? TBH, I haven’t even done any graphic design work yet under my new LLC but want to keep the name and business just in case I start. Not sure how much graphic design work I will end up doing in the long run.

Hope my post isn’t confusing!