Help! Which theme? There are so many.

Hi Everybody,
I have built a couple of pretty basic websites for my businesses. Both are off-line at the moment until I find a suitably protective, data protection text to put onto the websites, the Germans are very strict regarding this issue!
A student of mine checked one of the websites and said, rightfully, that the website needs a lot of work, she's right, it looks very unprofessional and a potential client for Business English (as a freelancer, I go to the companies and conduct, for the most part, in-house trainings) in the city of Hamburg, Germany, will probably be driven away.
I subscribed to Divi for a while but had little time to really get to grips with it, I was recommended something from Studiopress but, I believe I bought the wrong one, the pic space is so small, they are barely visible and make no impact at all and, I am not - as yet - familiar with CSS or is it PHP for WP.
I had a look at Thrive themes but, frankly I don't need 25 websites at the moment and the outlay, for a year, is currently a little steep.
I need a suitable but very easy to build theme for my Business English and for my other plans but, which are simple to build...that being said I haven't completed the course here at WA yet but, now that kindergarten has started again and the summer holidays/vacations are in full swing - a lot of lesson cancellations - I have a little more time and will be cracking on during the month of August before the holiday/vacation period has finished, with the WA course.
For any ideas and, I am sure there is a gigantic pool of experience here so that I perhaps I can glean some wisdom and go on to create truly appealing website, especially for the Business English and attract more direct clients but, I'd also like to offer my hypnosis skills too - something I am reactivating, after many years of being in a "hypnotic state myself" ;)because Business English, with a young family, is proving a little unreliable.
Many thanks for any input :)
Cheers
Rob