Blister on puppies paw?

Me

My puppy has had a blister type thing on his paw for about a week now. I just noticed it but my boyfriend said he saw it last week & forgot to mention it to me🙄. I don’t really see him licking at it that much but it looks really red/raw and painful! Should I take him to the vet or is there steps I should take beforehand? Idk if this is a minor problem or not as this is my first pet! Thanks in advance for your response!