Language schools In Germany

Hi All,

First post on the forum.

I have been learning Deutsch solo for around eight months now, four on LingQ asd its been a fantastic resource so far.

I am planning on spending a month in Germany v.soon to perhaps take a language course out there. Just some advice really.
I have had no experience with language schools, particularly the type where you can pretty much book in the day before you go. They seem to provide what I want (eg three lessons a day, 5 days a week for a month) and are fairly cheap but do they provide a good service? Also, I am 33 and though I realize I’ll probably be on the older end of the scale, I’d prefer not to be in a class of 16 year olds?

In terms of location, I have family in Heidelberg and know it well so I was thinking of spending time there or in Frankfurt. Am open to ideas though…