Remove wheel to clean ball bearings
I would not touch the bearings without the correct tools. You may get them apart, and will probably get them back together, but won't be able to adjust them very easily and won't be able to get the lock nut tight. 

For a novice, with the right tools, the job can be a but fiddly as getting the adjustment right will take a few goes. Without the right tools,a novice will likely take two steps back for each step forward. 

Given you do not have the tools, you have a few choices - by far the best is leave them alone if they wheel is running smoothly.  If you establish the bearings NEED fixing, be prepared to buy new cones and bearings and the cups could be hosed - you won't know till you get them apart what needs replacing. Two ways to do the job are to give it to your LBS, or buy some tools. 

If you choose to buy tools, its possible to pick up cheap tool kits that are although a low quality, will give the home mechanic all the tools needed for about 95% of repair jobs.    e.g. here Keep in mind cheap kits cost the same as one workshop quality tool, so be gentle - if things are rusted or over tight, they may do more damage than good.