I went to a hospital for ato get checkuped today.

People usually don't go to a hospital for a checkup, a hospital is suppose to be used if you have what you consider an emergency condition that requires immediate care. Usually you go to a doctor's office for a checkup.

I went to there by subway, but I didn't know where I was because I went out a different exit than usual.

'to' is not required here.

During the commute I checked where I was ion Google Maps app on my smartphone, when an old ladywoman approached me and asked me the way to a restaurant.

'During', what did you check. Please clarify when you did the checking. Using 'old woman' here is more polite than 'old lady'.

I thought in my heart that “I'm lost too, so I don't know, the way to the restaurant” but when I looked around, I saw a signboard ofor the restaurant, so I told her.

Using 'of the restaurant' here makes it sound like the signboard was used to make the signboard.

I was glad to able to thellp her.

'Help' is more appropriate here than 'tell'.

I couldwas able to get to the hospital soon after that.

Could sounds awkward here

I went to there by subway, but I didn't know where I was because I went out a different exit than usual.

During IAs I was checkeding where I was in Google Maps app on my smartphone, an old lady approached me and asked the way to a restaurant.

I thought into my heart thatself, “I'm lost too, so I don't know,” but when I looked around, I saw a signboard of the restaurant, so I told her.

I was glad to be able to tell her.

I went to athe hospital for a checkup today.

I went to there by subway, but I didn't know where I was because I went out a different exit than usual.

During IAs I was checkeding where I was in Google Maps app on my smartphone, an old lady approached me and asked me the way to a restaurant.

I thought into my heart thatself, “I'm lost, too, so I don't know,” but when I looked around, I saw a signboard of for the restaurant, so I told her.

よかった！

I was glad to be able to thellp her.

In the US, we usually say, "I'm glad I could help" so-and-so. It's like a set phrase.

I went to athe hospital for a checkup today.

I went to there by subway, b. But I didn't know where I was because I went out on a different exit than usual.

During IWhile checkeding where I was in Google Maps app on my smartphone, an old lady approached me and asked the way to a restaurant.

I thought in my heartd that “I'm lost too, so I don't know,” b. But when I looked around, I saw a signboard of the restaurant, s. So I told her.

I could get toarrived at the hospital soon after that.