Welcome to the Forum.
As S O D says, the machine should bear some resemblance to capability to produce what you intend to make on it. What it can produce will improve as you become more familiar with it.
But since your horizons will,expand, choose a machine that is a little larger than what you initially think will be the minimum.
With a secondhand machine, unless you know the history pretty conclusively, you take a chance, and could find a new hobby in refurbishing / repairing a machine tool. It could even be an A S P (All Spare Parts ) put together by someone with more interest in what it will fetch than how accurate / reliable / durable it will be.
So, you need to see and very carefully check a used machine. If you are unsure, take someone with you who DOES know what and how to check.
There are good secondhand machines out there. Quite often, tooling may be part of the package with a second, or more, hand machine.
Ex industry it is likely to have been driven hard almost 24 / 7. It was bought to make money, not to look pretty!
If you can still find one, an ex school / college machine will be relatively unworn, but may well bear the marks of unskilled / careless use, such as cuts into the table.
Chipped paint does not make a machine inaccurate; wear does!
DON'T buy unseen!
A new machine, from a reputable importer will have the advantage of a warranty, advice, spares, even replacement, if there are problems, Being a low budget hobby machine, you may well find the need for some fine tuning, but it will be more accurate than a badly worn, pre-abused machine. It may well have features that were not present when a 70 year old machine was designed and built..
Part of my training was on a machine driven by a flat belt from the motor, but still capable of good work!
A reputable supplier will or should, advise on what will be the best machine in their range for your purposes.
(I know one supplier who will refuse to sell a machine if it is going to be unsuitable for the buyer's purposes. )
He would rather lose a sale than have an unhappy customer telling their friends, and anyone else who will listen, that the machine and the supplier are rubbish! )
Your money; your choice, so choose carefully
HTH
Howard