Welcome! You can buy a humidity and temp monitor from homedepot for around $8. definitely worth the price. The humidity will be a factor in your grow, so you will need to try and monitor the levels. Ideally, in my opinion, 60-70% relative humidity during veg and 45-60% during flowering. (humidity should drop quite a bit during the last few weeks to prevent mold). But don't worry, cannabis will grow just fine outside of those boundaries. Depending on where you live, opening some windows may stabilize the humidity. Also for the size of your grow space, there are a number of very small, cheap dehumidifiers that could help. Good luck!