Most companies have a free version of their apps and rendering services. Most also have a trial, but I prefer to use the free until I get a good grip of the main features so I can get the best of the trial period to evaluate the app and service for good, and then choose which one is more adequate for my needs, workflow, etc. As I said it all depends on the needs, professional jobs demand higher levels of commitment and proficiency (and investment!) but also pay better, and so on.
Of course there are limitations in those free and test versions, but unless you need pro accuracy/deadline/resolution/quantity, IMHO it's the best way to learn and get proficient without cashing out big money right away. I mean, there are many different services and apps out there but ultimately they're just tools, and what really makes a difference is how we use them and not which one is the shinniest or most feature filled.
Now, answering your question more directly, if you want to play with simple yet easy, quick and rather decent 3D modeling you could try the new Aerial3D cloud service from FPV Camera. It's pretty nice and in fact I've been using its 3D Model auto capture app to get non-orthogonal sequential images from overhang or detailed objects for use with other more advanced rendering services. Some apps have flight planners only for ortho capturing and I had to do it manually which takes more time and involves more risk, and FPV's quite flexible and versatile with its fully automated 3 level independent multi-parameter settings.
You can also give 123D Catch free 3D model a look, it's pretty nice and more advanced than FPVs rendering and has all the other Autodesk 3D softs like ReMake (former Memento) to take your 3D needs and results to another level. Good luck!