Radio install?lautpsrecher? please help!

Good day, I bought a Polo3 2F bj 1994 did the car only 4 weeks, unfortunately without radio boxes:/ bought me today a cheap cassette radio and a couple of loudspeakers… we also come to my problem. maybe someone can take a bit of time and answer me in detail or contact me via ICQ 322789393 1. can I make the installation of the radio myself? have never done it and no experience etc? 2. what must I do and how do I best? have bissc He shoots to disconnect the battery I’m afraid I’ll get a wiped off… how do I clamp them off ? and can something happen there? 3. the speakers don’t fit in the storage (amenary board and trunk) bad? 4. can something get broken when installing the radio? can I do something wrong? thank you already