Questions & Answers about בטח יהיה בסדר אם נצא עכשיו; נראה שנגיע בזמן.
Here בטח means something like surely, probably, I’m sure, or it’ll be fine depending on tone.
In this sentence, it adds reassurance:
בטח יהיה בסדר = It’ll surely/probably be okay.
A learner should know that בטח is very common in spoken Hebrew and is often more conversational than a formal word like בוודאי.
Hebrew often uses an impersonal expression here.
יהיה בסדר literally looks like will be okay/fine, without stating a subject. In natural English, we usually add it:
It will be okay / It’ll be fine.
Hebrew does not always need an explicit subject in this kind of sentence. The masculine singular verb יהיה works as a general default form, almost like English it will be.