Now that it very easy to obtain a Linux Live there are certain prerequisites or conditions one must satisfy before experimenting with them.
I would list some of the mistakes I have done and continue to make in spite of the familiarity.
Some of them I call killer sharks.
The take over the entire system with minimum warning and they forget Live Booting is fun and game and there should no be any commitment to them like Microsoft Apple Mac as from the box.
1. First priority is the graphic capability. NVidia is the graphic card Linux find it easy to configure. Lot of manufacturers do not provide necessary OEM data for Linux to configure them. If you have the wrong card you may not be able to join the fun. They may boot up bit might do some damage to the card.
The damage may be due to wrong low level configuration or due to graphic intensity of the distribution. One example is SuSe which is graphic intensive KDE. On the other hand it may be like Swift Linux with low graphic intensity with the mind set for old computers and may not be suitable for graphic card with much power.
2. Second is the RAM. I recommend minimum of 1 GiB but more the merrier then the live session will be quite fast to boot and execute its virtues.
3. Third is the monitor. Lot of old distribution cannot configure LCD monitors. I of course in my early days with wrong horizontal and vertical configuration burnt few cathodes out of commission. Now of course most distributions tell you it has not got the driver for the card and uses the least harmful configuration for the live sessions.
4. If you have got a hard disk without an operating system or data no harm can be done. I often use the live session for preparing the hard disk. Partitioning and formatting can be done to get the hang of the process but with Operating system and data in the hard disk and no changes to the hard should be done without saving data.
5. Doing any of these without a UPS power supply is a risk. If power fails one should immediately terminate the session.