You are on the right track.
But yes, more than likely you'll need to change out the gas block to a low profile one to fit under a free float handguard unless you got a really short one.
It's not that difficult of a job if you are at least a little mechanically inclined. However if you don't have the tools already you may be better off getting a gunsmith to do the work for you.
ETA: if you are looking to improve your accuracy don't forget to look at your trigger. Alot of factory GI triggers are pretty crumby (and I'm not trigger snob).
Look at things like the ALG ACT trigger it the BCM PNT trigger. Not terribly expensive but a big improvement over most factory GI type triggers.
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There are lots of options for Drop In front rails.
I believe UTGs go for around $50.00.
Edit: ok so maybe $70.00.
https://www.midwayusa.com/product/2612198494/utg-pro-2-piece-handguard-quad-rail-ar-15-carbine-length
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But drop-in does not = free float.
I will add that those UTG Pro handguards are pretty nice. They have a lot of options.