The mutual fund company generally may not collapse - and that is a regulated financial company.
You are buying shares of the mutual fund - and manager is using your investing to purchase shares of other corporations or financial assets (bonds, etc).
Your investments are NOT protected and may loose values - so you need to be very careful in selecting mutual funds and analyzing their performance.
Also - it might be important to select the timing when you purchase certain mutual funds.
While it is possible to victim of a fraud - that is relatively rare - but positive investment results are not guaranteed.
There are several resources to screen mutual funds before purchasing - I will mention just a few
Please be aware - there are thousand of funds - and selection might be not a simple task.