@Ignacio Rosenberg you don't want to be "that person" who is talked about on social media by everyone for increasing rent on people who may even be out of work. It also puts you and your tenants on the wrong footing with a bad first impression.
Take care of your sweat equity tasks to make the place look a bit nicer. Hopefully we get out of this soon, the tenants will like that you are putting a little money in vs the last owner and it will likely facilitate an increase in rent if one is justified.
As to your idea of giving them a free month of rent then boosting it - does this make financial sense? If you dropped a month of rent you are losing $XXXX, if you increase it $150 you are ahead by only $1800 - $XXXX on the year. Is that worth it to you?
I personally would let this ride out first, only fix what is needed then get to sweat equity followed by a "not aggressive" increase. Vacancy is a real cost and in many cases it takes a few years to break even on an apartment remodel.