Hi Mendoza, welcome to the forum.
So although I certainly don't consider myself an expert

I am learning along with my son. I practice 4/5 times a week. Sometimes evyday and then life gets busy and I miss a week. I am making sound progress and am having lots of fun along the way. You really should consider having a go at it yourself. I am sure you will enjoy it and it is great for your child to see you playing.
So for your boy, to get good results and gradual ( but not predictable

) progress, the best thing to do is to practice every day. How long is less important than the daily practice. For 2.5 year old a session will probably last just 5 minutes ( possibly less

) at the beginning. If you could manage 2 short sessions daily you will see amazing results! Much faster results than paying for traditional piano lessons once a week. You will find that before long your child's focus will improve and your lessons will stretch out to 15 mins or more.
It is better to have a dedicated computer for the piano but we don't and we manage fine. We have a laptop plugged into the piano. I unplug it sometimes when I need more than the iPad, but mostly I just do my computer work at the piano now!

It is very important that you have the piano somewhere central to family life and low enough for baby. We have moved ours 3 times since we started and I am still not 100% happy with the location!

I would say just start with what you have and you will figure out quickly whether you need to locate another old computer or table or...house!