Income tax: if you rent out your gear on an "occasional basis" (in practice this is around a maximum of € 6000,- per year) there is really not much to worry about and you most likely do not have to pay income tax on this. However; in case of doubt for your specific situation we always recommend to contact the Tax Authority or a skilled tax advisor.
VAT: if it concerns a transaction between 2 private individuals, you do not have to pay VAT to the tax authorities. However, also in this case we recommend to contact a tax specialist of the Tax Authority for questions concerning your specific situation.