A Triumph cruiser is too heavy for most beginners, could break a leg, should work for now...
...but by all means, consider a used 250 Ninja or Honda to learn on.
Another school of thought offered by a Total Control Advanced Riding Course instructor when I asked about my wife starting out - before buying a bike, a beginner might consider taking the course with bike provided by the course. Some decide it's not for them, and don't get stuck holding a title and the associated depreciation. As a plus, your bike doesn't get subjected to a scratch & drop fest.
