It's my husband's birthday on the 27th and it's also going to be his first time celebrating father's day. Any tips on how to make it special without spending too much?

You can DIY some memorable cards or keepsakes for your husband for memories. E.g. baby's footprint and handprint card. Also, you can engage a photographer for a family photoshoot during his special day. I feel this will be a lifetime memories for 3 of you.