Local libraries often have a collection of comics. You could check your local library to see if they have TMNT comics. Another option is to visit your nearest comic book store. They usually stock a variety of comics, including TMNT.
You can try looking on popular comic book platforms like Comixology or Marvel Unlimited. They might have the original TMNT comics available for reading.
I'd say the IDW TMNT comics are worth checking out. They offer fresh takes on the characters and storylines while staying true to the essence. Also, the Archie Comics TMNT run has its own unique appeal and is a favorite among many fans.
You can try some well-known comic reading platforms like Comixology or Marvel Unlimited. They might have a collection of Flash comics available for online reading.
Some popular websites for reading Batman comics online are Comixology and Marvel Unlimited. These platforms offer a good selection and a user-friendly interface.