Cruiser style bikes are indeed perhaps not the best starting point for a cafe style build. However, it depends on how much fabrication work and experience you have. If your are really determined I think that is more important than how much skill and experience you have. Determination is what gives everyone skills and experience. You have two issues to solve in addition to all the things you would have to to on a more suitable starting platform. Cruiser style bikes generally have two distinct differences from their racier cousins: Low seat height and visually a longer and taller front end. If you can figure out how to "fix" these two things, then this platform becomes much the same as any other depending on the scope and scale of your intentions.
Fixing the seat height can be relatively simple as in simply adding structure to what you have. Alternatively, you can cut off what you have and fabricate a new "subframe" to replace it with. That is a big job for most people, but not terribly complicated and you likely won't get into too deep water engineering wise as long as you keep the rear shock length and mounting positions the same.
Altering the front end is another story entirely. To watch the internet, you'd think swapping out your front end was a no brainer. In reality it is anything but. Mechanically it isn't too bad, but even seemingly small changes can have a large impact on how your bike handles. On your 750, the engineers have done some things to fool your eye into thinking the front fork is longer and more steeply raked than it actually is. The lower fork legs are over long and extend below the axle. Mechanically, they are not all that much longer than a "normal" bike but the appearance is enhanced with the unneeded extra length. The rake is only a bit larger than normal, and the front axle is mounted in front of the fork legs to bring the trail back into a reasonable range. You can certainly and potentially fairly simply change the front end to suit, but it is important to understand what you want first, and make educated intentional choices. You likely are going to want steeper steering geometry and lower the front of the bike a bit. The way to start is to measure what you have first, rake, trail, fork offset, (really axle offset), and tire outside diameter. A little research will tell you what values for rake and trail are typical for sport bikes touring bikes, cruisers etc. Then when you consider making a change, say lowering the height if the steering stem, you will be able to generate what the new values will be and make a rational decision on what to do. There are plenty of on line calculators that let you plug in your bikes dimensions (or intended dimensions) and get the result. This will keep you in the ballpark of where you want to be and give you a pretty good shot of ending up with a decent handling motorcycle. Alternatively, you can guess (lots of people do with wildly varying results!). If this is more than you think you are up to, you likely will be better served to leave the front end engineering alone.
But don't despair! If your main focus is how it looks, you can do a great deal without redesigning the mechanics of your bike. Find a tank that is longer and less teardrop shaped and see what it will take to mount on the bike. Lower the bars. Lower the instruments. Kawasaki's designers made these things very high in the front to accentuate a "chopper" look. Choppers handle like shit, so Kawasaki was not able to actually build and sell such a thing. They had to cheat with some clever aesthetic characteristics. If you focus on "undoing" those things, you can then use the same tactic to make the bike look more "cafe" like than its chassis actually is. Since your bike was built high in front, considering clip on's is a lot more reasonable than on a "standard" bike because they won't be nearly as low. Getting all that hardware low will have a huge impact on the overall look without serious permanent alterations.
Whatever you do, ride around on your bike a LOT before you commit to a big plan. You want to be clear on what you want to change. You can take your entire motorcycle apart in a day, but it will take very considerably longer to put back together, so be careful on how big a bite you take!