Honestly, I think you need to start working out more consistently. Every 2 to 5 days is not consistent and if you expect to get results from that, you probably won't.
Strength training and muscle gain both require a lot of commitment to both your workout/training and your diet. It varies from person to person but expect 45 to 60 minute high intensity sessions at least 4 to 5 times a week. Use that as a guide to build on.
You might be consuming 2700 calories a day but not all calories are equal. You need high quality, nutrient dense calories - lots of proteins, fats and carbs from good quality natural foods. Stay away from that packaged garbage that is full of artificial colors, flavors and preservatives.
On the topic of calories, consume the same every day while trying to gain strength. When you want to cut/drop fat, then you can start cycling your calorie intake. You need to fuel your body.
If you are sore, tough it up and train through it anyway. If it really is that bad, try taking some magnesium each day. It will help with recovery.
Also look at split routines so you aren't directly training the same muscles each day. Do chest and triceps one day, front half of legs the next, back and biceps the next, rear half of legs next, then do core and bodyweight exercises - that's just a quick guide anyway.
Hope some of that helps.